find_package (PythonInterp REQUIRED)
find_package (OpenGL REQUIRED)
-find_package (ZLIB)
-find_package (DirectX)
+if (NOT WIN32)
+ # Always use the bundled zlib and libpng sources on Windows to make it easy
+ # to deploy the wrappers DLLs
+ find_package (ZLIB)
+ find_package (PNG)
+else (NOT WIN32)
+ find_package (DirectX)
+endif (NOT WIN32)
find_package (GLUT)
endif ()
# Use bundled ZLIB if system one can't be found
-if (NOT ZLIB_FOUND)
+if (ZLIB_FOUND)
+ include_directories (${ZLIB_INCLUDE_DIRS})
+ link_libraries (${ZLIB_LIBRARIES})
+else (ZLIB_FOUND)
add_library (zlib STATIC
zlib/adler32.c
zlib/compress.c
zlib/inftrees.c
zlib/inffast.c
)
-
include_directories (zlib)
link_libraries (zlib)
-else (NOT ZLIB_FOUND)
- include_directories (${ZLIB_INCLUDE_DIRS})
- link_libraries (${ZLIB_LIBRARIES})
-endif (NOT ZLIB_FOUND)
+endif (ZLIB_FOUND)
+
+# Use bundled LIBPNG if system one can't be found
+if (PNG_FOUND)
+ include_directories (${PNG_INCLUDE_DIR})
+ add_definitions (${PNG_DEFINITIONS})
+ link_libraries (${PNG_LIBRARIES})
+else (PNG_FOUND)
+ add_library (png STATIC
+ libpng/png.c
+ libpng/pngerror.c
+ libpng/pngget.c
+ libpng/pngmem.c
+ libpng/pngpread.c
+ libpng/pngread.c
+ libpng/pngrio.c
+ libpng/pngrtran.c
+ libpng/pngrutil.c
+ libpng/pngset.c
+ libpng/pngtrans.c
+ libpng/pngwio.c
+ libpng/pngwrite.c
+ libpng/pngwtran.c
+ libpng/pngwutil.c
+ )
+ include_directories (libpng)
+ link_libraries (png)
+endif (PNG_FOUND)
include_directories (${CMAKE_CURRENT_SOURCE_DIR})
--- /dev/null
+
+Libpng 1.4.4 - September 23, 2010
+
+This is a public release of libpng, intended for use in production codes.
+
+Files available for download:
+
+Source files with LF line endings (for Unix/Linux) and with a
+"configure" script
+
+ libpng-1.4.4.tar.xz (LZMA-compressed, recommended)
+ libpng-1.4.4.tar.gz
+ libpng-1.4.4.tar.bz2
+
+Source files with CRLF line endings (for Windows), without the
+"configure" script
+
+ lpng144.zip
+ lpng144.7z
+
+Other information:
+
+ libpng-1.4.4-README.txt
+ libpng-1.4.4-LICENSE.txt
+
+Changes since the last public release (1.4.3):
+ Removed extraneous new_push_process_row.c file.
+ Revised the "SEE ALSO" style of libpng.3, libpngpf.3, and png.5
+ Removed some newly-added TAB characters from pngpread.c.
+ Fixed some indentation in pngpread.c and pngrutil.c
+ Changed "extern PNG_EXPORT" to "PNG_EXPORT" in png.h (Jan Nijtmans)
+ Changed "extern" to "PNG_EXTERN" in pngpriv.h (except for the 'extern "C" {')
+ Put "#ifndef PNG_EXTERN, #endif" around "#define PNG_EXTERN" in pngpriv.h
+ Added -DNO_PNG_SNPRINTF to CFLAGS in scripts/makefile.dj2
+ Moved the definition of png_snprintf() outside of the enclosing
+ #ifdef blocks in pngconf.h
+ Made a special case "#define PNGAPI" in pngconf.h for WATCOM.
+ Removed reference to cbuilder5/* from Makefile.in and Makefile.am
+ Updated the read macros and functions from 1.5.0beta38.
+ Updated projects/visualc71 so it can find scripts/pnglibconf.h
+ Removed unused png_mem_* defines from pngconf.h.
+ Correct use of _WINDOWS_ in pngconf.h
+ Don't try to use version-script with cygwin/mingw.
+ Revised contrib/gregbook to work under cygwin/mingw.
+ Updated prebuilt aclocal.m4 and ltmain.sh
+ Add .dll.a to the list of extensions to be symlinked by Makefile.am (Yaakov)
+ Updated CMakelists.txt to use CMAKE_INSTALL_LIBDIR variable; useful for
+ installing libpng in /usr/lib64 (Funda Wang).
+ Revised CMakeLists.txt to put the man pages in share/man/man* not man/man*
+ Revised CMakeLists.txt to make symlinks instead of copies when installing.
+ Moved "#include pngusr.h" ahead of PNG_USER_PRIVATEBUILD test in pngconf.h
+ Eliminated a deprecated reference to png_ptr->io_ptr in pngtest.c
+ Eliminated new unnecessary #if tests regarding the sCAL chunk from pngrutil.c
+ Updated the xcode project to work with libpng-1.4.x and added iOS targets
+ for simulator and device (Philippe Hausler).
+ Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER,
+ $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
+ Rebuilt configure scripts with automake-1.11.1 instead of automake-1.11.
+ Removed unused mkinstalldirs file.
+
+Send comments/corrections/commendations to glennrp at users.sourceforge.net
+or to png-mng-implement at lists.sf.net (subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement).
+
+Glenn R-P
--- /dev/null
+#if 0
+libpng_changes(){ /*
+CHANGES - changes for libpng
+
+version 0.2
+ added reader into png.h
+ fixed small problems in stub file
+
+version 0.3
+ added pull reader
+ split up pngwrite.c to several files
+ added pnglib.txt
+ added example.c
+ cleaned up writer, adding a few new transformations
+ fixed some bugs in writer
+ interfaced with zlib 0.5
+ added K&R support
+ added check for 64 KB blocks for 16 bit machines
+
+version 0.4
+ cleaned up code and commented code
+ simplified time handling into png_time
+ created png_color_16 and png_color_8 to handle color needs
+ cleaned up color type defines
+ fixed various bugs
+ made various names more consistent
+ interfaced with zlib 0.71
+ cleaned up zTXt reader and writer (using zlib's Reset functions)
+ split transformations into pngrtran.c and pngwtran.c
+
+version 0.5
+ interfaced with zlib 0.8
+ fixed many reading and writing bugs
+ saved using 3 spaces instead of tabs
+
+version 0.6
+ added png_large_malloc() and png_large_free()
+ added png_size_t
+ cleaned up some compiler warnings
+ added png_start_read_image()
+
+version 0.7
+ cleaned up lots of bugs
+ finished dithering and other stuff
+ added test program
+ changed name from pnglib to libpng
+
+version 0.71 [June, 1995]
+ changed pngtest.png for zlib 0.93
+ fixed error in libpng.txt and example.c
+
+version 0.8
+ cleaned up some bugs
+ added png_set_filler()
+ split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
+ added #define's to remove unwanted code
+ moved png_info_init() to png.c
+ added old_size into png_realloc()
+ added functions to manually set filtering and compression info
+ changed compression parameters based on image type
+ optimized filter selection code
+ added version info
+ changed external functions passing floats to doubles (k&r problems?)
+ put all the configurable stuff in pngconf.h
+ enabled png_set_shift to work with paletted images on read
+ added png_read_update_info() - updates info structure with
+ transformations
+
+version 0.81 [August, 1995]
+ incorporated Tim Wegner's medium model code (thanks, Tim)
+
+version 0.82 [September, 1995]
+ [unspecified changes]
+
+version 0.85 [December, 1995]
+ added more medium model code (almost everything's a far)
+ added i/o, error, and memory callback functions
+ fixed some bugs (16 bit, 4 bit interlaced, etc.)
+ added first run progressive reader (barely tested)
+
+version 0.86 [January, 1996]
+ fixed bugs
+ improved documentation
+
+version 0.87 [January, 1996]
+ fixed medium model bugs
+ fixed other bugs introduced in 0.85 and 0.86
+ added some minor documentation
+
+version 0.88 [January, 1996]
+ fixed progressive bugs
+ replaced tabs with spaces
+ cleaned up documentation
+ added callbacks for read/write and warning/error functions
+
+version 0.89 [July, 1996]
+ added new initialization API to make libpng work better with shared libs
+ we now have png_create_read_struct(), png_create_write_struct(),
+ png_create_info_struct(), png_destroy_read_struct(), and
+ png_destroy_write_struct() instead of the separate calls to
+ malloc and png_read_init(), png_info_init(), and png_write_init()
+ changed warning/error callback functions to fix bug - this means you
+ should use the new initialization API if you were using the old
+ png_set_message_fn() calls, and that the old API no longer exists
+ so that people are aware that they need to change their code
+ changed filter selection API to allow selection of multiple filters
+ since it didn't work in previous versions of libpng anyways
+ optimized filter selection code
+ fixed png_set_background() to allow using an arbitrary RGB color for
+ paletted images
+ fixed gamma and background correction for paletted images, so
+ png_correct_palette is not needed unless you are correcting an
+ external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
+ in pngconf.h) - if nobody uses this, it may disappear in the future.
+ fixed bug with Borland 64K memory allocation (Alexander Lehmann)
+ fixed bug in interlace handling (Smarasderagd, I think)
+ added more error checking for writing and image to reduce invalid files
+ separated read and write functions so that they won't both be linked
+ into a binary when only reading or writing functionality is used
+ new pngtest image also has interlacing and zTXt
+ updated documentation to reflect new API
+
+version 0.90 [January, 1997]
+ made CRC errors/warnings on critical and ancillary chunks configurable
+ libpng will use the zlib CRC routines by (compile-time) default
+ changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
+ added external C++ wrapper statements to png.h (Gilles Dauphin)
+ allow PNG file to be read when some or all of file signature has already
+ been read from the beginning of the stream. ****This affects the size
+ of info_struct and invalidates all programs that use a shared libpng****
+ fixed png_filler() declarations
+ fixed? background color conversions
+ fixed order of error function pointers to match documentation
+ current chunk name is now available in png_struct to reduce the number
+ of nearly identical error messages (will simplify multi-lingual
+ support when available)
+ try to get ready for unknown-chunk callback functions:
+ - previously read critical chunks are flagged, so the chunk handling
+ routines can determine if the chunk is in the right place
+ - all chunk handling routines have the same prototypes, so we will
+ be able to handle all chunks via a callback mechanism
+ try to fix Linux "setjmp" buffer size problems
+ removed png_large_malloc, png_large_free, and png_realloc functions.
+
+version 0.95 [March, 1997]
+ fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
+ fixed bug in PNG file signature compares when start != 0
+ changed parameter type of png_set_filler(...filler...) from png_byte
+ to png_uint_32
+ added test for MACOS to ensure that both math.h and fp.h are not #included
+ added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
+ added "packswap" transformation, which changes the endianness of
+ packed-pixel bytes (Kevin Bracey)
+ added "strip_alpha" transformation, which removes the alpha channel of
+ input images without using it (not necessarily a good idea)
+ added "swap_alpha" transformation, which puts the alpha channel in front
+ of the color bytes instead of after
+ removed all implicit variable tests which assume NULL == 0 (I think)
+ changed several variables to "png_size_t" to show 16/32-bit limitations
+ added new pCAL chunk read/write support
+ added experimental filter selection weighting (Greg Roelofs)
+ removed old png_set_rgbx() and png_set_xrgb() functions that have been
+ obsolete for about 2 years now (use png_set_filler() instead)
+ added macros to read 16- and 32-bit ints directly from buffer, to be
+ used only on those systems that support it (namely PowerPC and 680x0)
+ With some testing, this may become the default for MACOS/PPC systems.
+ only calculate CRC on data if we are going to use it
+ added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
+ added macros for simple libpng debugging output selectable at compile time
+ removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
+ more description of info_struct in libpng.txt and png.h
+ more instructions in example.c
+ more chunk types tested in pngtest.c
+ renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
+ png_set_<chunk>. We now have corresponding png_get_<chunk>
+ functions in pngget.c to get information in info_ptr. This isolates
+ the application from the internal organization of png_info_struct
+ (good for shared library implementations).
+
+version 0.96 [May, 1997]
+ fixed serious bug with < 8bpp images introduced in 0.95
+ fixed 256-color transparency bug (Greg Roelofs)
+ fixed up documentation (Greg Roelofs, Laszlo Nyul)
+ fixed "error" in pngconf.h for Linux setjmp() behaviour
+ fixed DOS medium model support (Tim Wegner)
+ fixed png_check_keyword() for case with error in static string text
+ added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
+ added typecasts to quiet compiler errors
+ added more debugging info
+
+version 0.97 [January, 1998]
+ removed PNG_USE_OWN_CRC capability
+ relocated png_set_crc_action from pngrutil.c to pngrtran.c
+ fixed typecasts of "new_key", etc. (Andreas Dilger)
+ added RFC 1152 [sic] date support
+ fixed bug in gamma handling of 4-bit grayscale
+ added 2-bit grayscale gamma handling (Glenn R-P)
+ added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
+ minor corrections in libpng.txt
+ added simple sRGB support (Glenn R-P)
+ easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
+ all configurable options can be selected from command-line instead
+ of having to edit pngconf.h (Glenn R-P)
+ fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
+ added more conditions for png_do_background, to avoid changing
+ black pixels to background when a background is supplied and
+ no pixels are transparent
+ repaired PNG_NO_STDIO behaviour
+ tested NODIV support and made it default behaviour (Greg Roelofs)
+ added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
+ regularized version numbering scheme and bumped shared-library major
+ version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs)
+
+version 0.98 [January, 1998]
+ cleaned up some typos in libpng.txt and in code documentation
+ fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
+ cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
+ changed recommendation about file_gamma for PC images to .51 from .45,
+ in example.c and libpng.txt, added comments to distinguish between
+ screen_gamma, viewing_gamma, and display_gamma.
+ changed all references to RFC1152 to read RFC1123 and changed the
+ PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
+ added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
+ changed srgb_intent from png_byte to int to avoid compiler bugs
+
+version 0.99 [January 30, 1998]
+ free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
+ fixed a longstanding "packswap" bug in pngtrans.c
+ fixed some inconsistencies in pngconf.h that prevented compiling with
+ PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
+ fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
+ changed recommendation about file_gamma for PC images to .50 from .51 in
+ example.c and libpng.txt, and changed file_gamma for sRGB images to .45
+ added a number of functions to access information from the png structure
+ png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
+ added TARGET_MACOS similar to zlib-1.0.8
+ define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
+ added type casting to all png_malloc() function calls
+version 0.99a [January 31, 1998]
+ Added type casts and parentheses to all returns that return a value.(Tim W.)
+version 0.99b [February 4, 1998]
+ Added type cast png_uint_32 on malloc function calls where needed.
+ Changed type of num_hist from png_uint_32 to int (same as num_palette).
+ Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
+ Renamed makefile.elf to makefile.lnx.
+version 0.99c [February 7, 1998]
+ More type casting. Removed erroneous overflow test in pngmem.c.
+ Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
+ Added UNIX manual pages libpng.3 (incorporating libpng.txt) and png.5.
+version 0.99d [February 11, 1998]
+ Renamed "far_to_near()" "png_far_to_near()"
+ Revised libpng.3
+ Version 99c "buffered" operations didn't work as intended. Replaced them
+ with png_memcpy_check() and png_memset_check().
+ Added many "if (png_ptr == NULL) return" to quell compiler warnings about
+ unused png_ptr, mostly in pngget.c and pngset.c.
+ Check for overlength tRNS chunk present when indexed-color PLTE is read.
+ Cleaned up spelling errors in libpng.3/libpng.txt
+ Corrected a problem with png_get_tRNS() which returned undefined trans array
+version 0.99e [February 28, 1998]
+ Corrected png_get_tRNS() again.
+ Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
+ Touched up example.c to make more of it compileable, although the entire
+ file still can't be compiled (Willem van Schaik)
+ Fixed a bug in png_do_shift() (Bryan Tsai)
+ Added a space in png.h prototype for png_write_chunk_start()
+ Replaced pngtest.png with one created with zlib 1.1.1
+ Changed pngtest to report PASS even when file size is different (Jean-loup G.)
+ Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)
+version 0.99f [March 5, 1998]
+ Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
+ Moved makefiles into a "scripts" directory, and added INSTALL instruction file
+ Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
+ Added pointers to "note on libpng versions" in makefile.lnx and README
+ Added row callback feature when reading and writing nonprogressive rows
+ and added a test of this feature in pngtest.c
+ Added user transform callbacks, with test of the feature in pngtest.c
+version 0.99g [March 6, 1998, morning]
+ Minor changes to pngtest.c to suppress compiler warnings.
+ Removed "beta" language from documentation.
+version 0.99h [March 6, 1998, evening]
+ Minor changes to previous minor changes to pngtest.c
+ Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
+ and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
+ Added user transform capability
+
+version 1.00 [March 7, 1998]
+ Changed several typedefs in pngrutil.c
+ Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
+ replaced "while(1)" with "for(;;)"
+ added PNGARG() to prototypes in pngtest.c and removed some prototypes
+ updated some of the makefiles (Tom Lane)
+ changed some typedefs (s_start, etc.) in pngrutil.c
+ fixed dimensions of "short_months" array in pngwrite.c
+ Replaced ansi2knr.c with the one from jpeg-v6
+
+version 1.0.0 [March 8, 1998]
+ Changed name from 1.00 to 1.0.0 (Adam Costello)
+ Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
+version 1.0.0a [March 9, 1998]
+ Fixed three bugs in pngrtran.c to make gamma+background handling consistent
+ (Greg Roelofs)
+ Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
+ for major, minor, and bugfix releases. This is 10001. (Adam Costello,
+ Tom Lane)
+ Make months range from 1-12 in png_convert_to_rfc1123
+version 1.0.0b [March 13, 1998]
+ Quieted compiler complaints about two empty "for" loops in pngrutil.c
+ Minor changes to makefile.s2x
+ Removed #ifdef/#endif around a png_free() in pngread.c
+
+version 1.0.1 [March 14, 1998]
+ Changed makefile.s2x to reduce security risk of using a relative pathname
+ Fixed some typos in the documentation (Greg).
+ Fixed a problem with value of "channels" returned by png_read_update_info()
+version 1.0.1a [April 21, 1998]
+ Optimized Paeth calculations by replacing abs() function calls with intrinsics
+ plus other loop optimizations. Improves avg decoding speed by about 20%.
+ Commented out i386istic "align" compiler flags in makefile.lnx.
+ Reduced the default warning level in some makefiles, to make them consistent.
+ Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
+ Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
+ Added grayscale and 16-bit capability to png_do_read_filler().
+ Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
+ too large when writing an image with bit_depth < 8 (Bob Dellaca).
+ Corrected some bugs in the experimental weighted filtering heuristics.
+ Moved a misplaced pngrutil code block that truncates tRNS if it has more
+ than num_palette entries -- test was done before num_palette was defined.
+ Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
+ Changed compiler flags in makefile.wat for better optimization (Pawel Mrochen).
+version 1.0.1b [May 2, 1998]
+ Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
+ Relocated the png_composite macros from pngrtran.c to png.h (Greg).
+ Added makefile.sco (contributed by Mike Hopkirk).
+ Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
+ Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
+ More work on the Paeth-filtering, achieving imperceptible speedup (A Kleinert).
+ More work on loop optimization which may help when compiled with C++ compilers.
+ Added warnings when people try to use transforms they've defined out.
+ Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
+ Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
+version 1.0.1c [May 11, 1998]
+ Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
+ filler bytes should have been 0xff instead of 0xf.
+ Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
+ Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
+ out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
+ Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
+ for consistency, in pngconf.h
+ Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier
+ to remove unwanted capabilities via the compile line
+ Made some corrections to grammar (which, it's) in documentation (Greg).
+ Corrected example.c, use of row_pointers in png_write_image().
+version 1.0.1d [May 24, 1998]
+ Corrected several statements that used side effects illegally in pngrutil.c
+ and pngtrans.c, that were introduced in version 1.0.1b
+ Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
+ More corrections to example.c, use of row_pointers in png_write_image()
+ and png_read_rows().
+ Added pngdll.mak and pngdef.pas to scripts directory, contributed by
+ Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
+ Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
+ Changed several loops from count-down to count-up, for consistency.
+version 1.0.1e [June 6, 1998]
+ Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
+ added warnings when people try to set png_read_fn and png_write_fn in
+ the same structure.
+ Added a test such that png_do_gamma will be done when num_trans==0
+ for truecolor images that have defined a background. This corrects an
+ error that was introduced in libpng-0.90 that can cause gamma processing
+ to be skipped.
+ Added tests in png.h to include "trans" and "trans_values" in structures
+ when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined.
+ Add png_free(png_ptr->time_buffer) in png_destroy_read_struct()
+ Moved png_convert_to_rfc_1123() from pngwrite.c to png.c
+ Added capability for user-provided malloc_fn() and free_fn() functions,
+ and revised pngtest.c to demonstrate their use, replacing the
+ PNGTEST_DEBUG_MEM feature.
+ Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
+
+version 1.0.2 [June 14, 1998]
+ Fixed two bugs in makefile.bor .
+version 1.0.2a [December 30, 1998]
+ Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
+ Fixed a bug in png_do_filler() that made it fail to write filler bytes in
+ the left-most pixel of each row (Kevin Bracey).
+ Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
+ in pngtest.c (Duncan Simpson).
+ Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
+ even when no tIME chunk was present in the source file.
+ Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
+ Fixed a problem in png_read_push_finish_row(), which would not skip some
+ passes that it should skip, for images that are less than 3 pixels high.
+ Interchanged the order of calls to png_do_swap() and png_do_shift()
+ in pngwtran.c (John Cromer).
+ Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
+ Changed "bad adaptive filter type" from error to warning in pngrutil.c .
+ Fixed a documentation error about default filtering with 8-bit indexed-color.
+ Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
+ (L. Peter Deutsch).
+ Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
+ Added png_get_copyright() and png_get_header_version() functions.
+ Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
+ Added information about debugging in libpng.txt and libpng.3 .
+ Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and makefile.sco.
+ Removed lines after Dynamic Dependencies" in makefile.aco .
+ Revised makefile.dec to make a shared library (Jeremie Petit).
+ Removed trailing blanks from all files.
+version 1.0.2a [January 6, 1999]
+ Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
+ Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
+ Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
+ Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
+ which is obsolete.
+
+version 1.0.3 [January 14, 1999]
+ Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
+ Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO.
+version 1.0.3a [August 12, 1999]
+ Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
+ if an attempt is made to read an interlaced image when it's not supported.
+ Added check if png_ptr->trans is defined before freeing it in pngread.c
+ Modified the Y2K statement to include versions back to version 0.71
+ Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
+ Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments)
+ Replaced leading blanks with tab characters in makefile.hux
+ Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
+ Changed (float)red and (float)green to (double)red, (double)green
+ in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
+ Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
+ Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
+ Updated documentation to refer to the PNG-1.2 specification.
+ Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c
+ in makefile.knr, INSTALL, and README (L. Peter Deutsch)
+ Fixed bugs in calculation of the length of rowbytes when adding alpha
+ channels to 16-bit images, in pngrtran.c (Chris Nokleberg)
+ Added function png_set_user_transform_info() to store user_transform_ptr,
+ user_depth, and user_channels into the png_struct, and a function
+ png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
+ Added function png_set_empty_plte_permitted() to make libpng useable
+ in MNG applications.
+ Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
+ Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
+ consistent with PNG-1.2, and allow variance of 500 before complaining.
+ Added assembler code contributed by Intel in file pngvcrd.c and modified
+ makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation, Gilles Vollant)
+ Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
+ Added some aliases for png_set_expand() in pngrtran.c, namely
+ png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
+ (Greg Roelofs, in "PNG: The Definitive Guide").
+ Added makefile.beo for BEOS on X86, contributed by Sander Stok.
+version 1.0.3b [August 26, 1999]
+ Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
+ Changed leading blanks to tabs in all makefiles.
+ Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
+ Made alternate versions of png_set_expand() in pngrtran.c, namely
+ png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
+ (Greg Roelofs, in "PNG: The Definitive Guide"). Deleted the 1.0.3a aliases.
+ Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
+ Revised calculation of num_blocks in pngmem.c to avoid a potentially
+ negative shift distance, whose results are undefined in the C language.
+ Added a check in pngset.c to prevent writing multiple tIME chunks.
+ Added a check in pngwrite.c to detect invalid small window_bits sizes.
+version 1.0.3d [September 4, 1999]
+ Fixed type casting of igamma in pngrutil.c
+ Added new png_expand functions to scripts/pngdef.pas and pngos2.def
+ Added a demo read_user_transform_fn that examines the row filters in pngtest.c
+
+version 1.0.4 [September 24, 1999]
+ Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
+ Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
+ Made several minor corrections to pngtest.c
+ Renamed the makefiles with longer but more user friendly extensions.
+ Copied the PNG copyright and license to a separate LICENSE file.
+ Revised documentation, png.h, and example.c to remove reference to
+ "viewing_gamma" which no longer appears in the PNG specification.
+ Revised pngvcrd.c to use MMX code for interlacing only on the final pass.
+ Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a
+ Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX
+ assembler code) and makefile.vcwin32 (doesn't).
+ Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
+ Added a copy of pngnow.png to the distribution.
+version 1.0.4a [September 25, 1999]
+ Increase max_pixel_depth in pngrutil.c if a user transform needs it.
+ Changed several division operations to right-shifts in pngvcrd.c
+version 1.0.4b [September 30, 1999]
+ Added parentheses in line 3732 of pngvcrd.c
+ Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1
+version 1.0.4c [October 1, 1999]
+ Added a "png_check_version" function in png.c and pngtest.c that will generate
+ a helpful compiler error if an old png.h is found in the search path.
+ Changed type of png_user_transform_depth|channels from int to png_byte.
+version 1.0.4d [October 6, 1999]
+ Changed 0.45 to 0.45455 in png_set_sRGB()
+ Removed unused PLTE entries from pngnow.png
+ Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly.
+version 1.0.4e [October 10, 1999]
+ Fixed sign error in pngvcrd.c (Greg Roelofs)
+ Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P)
+version 1.0.4f [October 15, 1999]
+ Surrounded example.c code with #if 0 .. #endif to prevent people from
+ inadvertently trying to compile it.
+ Changed png_get_header_version() from a function to a macro in png.h
+ Added type casting mostly in pngrtran.c and pngwtran.c
+ Removed some pointless "ptr = NULL" in pngmem.c
+ Added a "contrib" directory containing the source code from Greg's book.
+
+version 1.0.5 [October 15, 1999]
+ Minor editing of the INSTALL and README files.
+version 1.0.5a [October 23, 1999]
+ Added contrib/pngsuite and contrib/pngminus (Willem van Schaik)
+ Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans)
+ Further optimization and bugfix of pngvcrd.c
+ Revised pngset.c so that it does not allocate or free memory in the user's
+ text_ptr structure. Instead, it makes its own copy.
+ Created separate write_end_info_struct in pngtest.c for a more severe test.
+ Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak.
+version 1.0.5b [November 23, 1999]
+ Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and
+ PNG_FLAG_WROTE_tIME from flags to mode.
+ Added png_write_info_before_PLTE() function.
+ Fixed some typecasting in contrib/gregbook/*.c
+ Updated scripts/makevms.com and added makevms.com to contrib/gregbook
+ and contrib/pngminus (Martin Zinser)
+version 1.0.5c [November 26, 1999]
+ Moved png_get_header_version from png.h to png.c, to accommodate ansi2knr.
+ Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to
+ accommodate making DLL's: Moved usr_png_ver from global variable to function
+ png_get_header_ver() in png.c. Moved png_sig to png_sig_bytes in png.c and
+ eliminated use of png_sig in pngwutil.c. Moved the various png_CHNK arrays
+ into pngtypes.h. Eliminated use of global png_pass arrays. Declared the
+ png_CHNK and png_pass arrays to be "const". Made the global arrays
+ available to applications (although none are used in libpng itself) when
+ PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined.
+ Removed some extraneous "-I" from contrib/pngminus/makefile.std
+ Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2.
+ Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3
+version 1.0.5d [November 29, 1999]
+ Add type cast (png_const_charp) two places in png.c
+ Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays.
+ Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available
+ to applications a macro "PNG_USE_LOCAL_ARRAYS".
+ comment out (with #ifdef) all the new declarations when
+ PNG_USE_GLOBAL_ARRAYS is defined.
+ Added PNG_EXPORT_VAR macro to accommodate making DLL's.
+version 1.0.5e [November 30, 1999]
+ Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text
+ structure; refactored the inflate/deflate support to make adding new chunks
+ with trailing compressed parts easier in the future, and added new functions
+ png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP,
+ png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond).
+ NOTE: Applications that write text chunks MUST define png_text->lang
+ before calling png_set_text(). It must be set to NULL if you want to
+ write tEXt or zTXt chunks. If you want your application to be able to
+ run with older versions of libpng, use
+
+ #ifdef PNG_iTXt_SUPPORTED
+ png_text[i].lang = NULL;
+ #endif
+
+ Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned
+ offsets (Eric S. Raymond).
+ Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into
+ PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED
+ macros, leaving the separate macros also available.
+ Removed comments on #endifs at the end of many short, non-nested #if-blocks.
+version 1.0.5f [December 6, 1999]
+ Changed makefile.solaris to issue a warning about potential problems when
+ the ucb "ld" is in the path ahead of the ccs "ld".
+ Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3.
+ Added sCAL chunk support (Eric S. Raymond).
+version 1.0.5g [December 7, 1999]
+ Fixed "png_free_spallettes" typo in png.h
+ Added code to handle new chunks in pngpread.c
+ Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block
+ Added "translated_key" to png_text structure and png_write_iTXt().
+ Added code in pngwrite.c to work around a newly discovered zlib bug.
+version 1.0.5h [December 10, 1999]
+ NOTE: regarding the note for version 1.0.5e, the following must also
+ be included in your code:
+ png_text[i].translated_key = NULL;
+ Unknown chunk handling is now supported.
+ Option to eliminate all floating point support was added. Some new
+ fixed-point functions such as png_set_gAMA_fixed() were added.
+ Expanded tabs and removed trailing blanks in source files.
+version 1.0.5i [December 13, 1999]
+ Added some type casts to silence compiler warnings.
+ Renamed "png_free_spalette" to "png_free_spalettes" for consistency.
+ Removed leading blanks from a #define in pngvcrd.c
+ Added some parameters to the new png_set_keep_unknown_chunks() function.
+ Added a test for up->location != 0 in the first instance of writing
+ unknown chunks in pngwrite.c
+ Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to
+ prevent recursion.
+ Added png_free_hIST() function.
+ Various patches to fix bugs in the sCAL and integer cHRM processing,
+ and to add some convenience macros for use with sCAL.
+version 1.0.5j [December 21, 1999]
+ Changed "unit" parameter of png_write_sCAL from png_byte to int, to work
+ around buggy compilers.
+ Added new type "png_fixed_point" for integers that hold float*100000 values
+ Restored backward compatibility of tEXt/zTXt chunk processing:
+ Restored the first four members of png_text to the same order as v.1.0.5d.
+ Added members "lang_key" and "itxt_length" to png_text struct. Set
+ text_length=0 when "text" contains iTXt data. Use the "compression"
+ member to distinguish among tEXt/zTXt/iTXt types. Added
+ PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros.
+ The "Note" above, about backward incompatibility of libpng-1.0.5e, no
+ longer applies.
+ Fixed png_read|write_iTXt() to read|write parameters in the right order,
+ and to write the iTXt chunk after IDAT if it appears in the end_ptr.
+ Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs)
+ Reversed the order of trying to write floating-point and fixed-point gAMA.
+version 1.0.5k [December 27, 1999]
+ Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))"
+ Added png_handle_as_unknown() function (Glenn)
+ Added png_free_chunk_list() function and chunk_list and num_chunk_list members
+ of png_ptr.
+ Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE.
+ Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings
+ about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored)
+ Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR).
+ Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is.
+ Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP().
+version 1.0.5l [January 1, 2000]
+ Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr()
+ for setting a callback function to handle unknown chunks and for
+ retrieving the associated user pointer (Glenn).
+version 1.0.5m [January 7, 2000]
+ Added high-level functions png_read_png(), png_write_png(), png_free_pixels().
+version 1.0.5n [January 9, 2000]
+ Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its
+ own memory for info_ptr->palette. This makes it safe for the calling
+ application to free its copy of the palette any time after it calls
+ png_set_PLTE().
+version 1.0.5o [January 20, 2000]
+ Cosmetic changes only (removed some trailing blanks and TABs)
+version 1.0.5p [January 31, 2000]
+ Renamed pngdll.mak to makefile.bd32
+ Cosmetic changes in pngtest.c
+version 1.0.5q [February 5, 2000]
+ Relocated the makefile.solaris warning about PATH problems.
+ Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
+ Revised makefile.gcmmx
+ Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros
+version 1.0.5r [February 7, 2000]
+ Removed superfluous prototype for png_get_itxt from png.h
+ Fixed a bug in pngrtran.c that improperly expanded the background color.
+ Return *num_text=0 from png_get_text() when appropriate, and fix documentation
+ of png_get_text() in libpng.txt/libpng.3.
+version 1.0.5s [February 18, 2000]
+ Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
+ new error handler that's planned for the next libpng release, and changed
+ example.c, pngtest.c, and contrib programs to use this macro.
+ Revised some of the DLL-export macros in pngconf.h (Greg Roelofs)
+ Fixed a bug in png_read_png() that caused it to fail to expand some images
+ that it should have expanded.
+ Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions
+ in pngget.c
+ Changed the allocation of palette, history, and trans arrays back to
+ the version 1.0.5 method (linking instead of copying) which restores
+ backward compatibility with version 1.0.5. Added some remarks about
+ that in example.c. Added "free_me" member to info_ptr and png_ptr
+ and added png_free_data() function.
+ Updated makefile.linux and makefile.gccmmx to make directories conditionally.
+ Made cosmetic changes to pngasmrd.h
+ Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
+ Modified png_read_png() to allocate info_ptr->row_pointers only if it
+ hasn't already been allocated.
+version 1.0.5t [March 4, 2000]
+ Changed png_jmp_env() migration aiding macro to png_jmpbuf().
+ Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c
+ Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when
+ PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b
+ Files in contrib/gregbook were revised to use png_jmpbuf() and to select
+ a 24-bit visual if one is available, and to allow abbreviated options.
+ Files in contrib/pngminus were revised to use the png_jmpbuf() macro.
+ Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s
+version 1.0.5u [March 5, 2000]
+ Simplified the code that detects old png.h in png.c and pngtest.c
+ Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp)
+ Increased precision of rgb_to_gray calculations from 8 to 15 bits and
+ added png_set_rgb_to_gray_fixed() function.
+ Added makefile.bc32 (32-bit Borland C++, C mode)
+version 1.0.5v [March 11, 2000]
+ Added some parentheses to the png_jmpbuf macro definition.
+ Updated references to the zlib home page, which has moved to freesoftware.com.
+ Corrected bugs in documentation regarding png_read_row() and png_write_row().
+ Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt.
+ Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3,
+ revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin)
+
+version 1.0.6 [March 20, 2000]
+ Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
+ Added makefile.sggcc (SGI IRIX with gcc)
+version 1.0.6d [April 7, 2000]
+ Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
+ Added data_length parameter to png_decompress_chunk() function
+ Revised documentation to remove reference to abandoned png_free_chnk functions
+ Fixed an error in png_rgb_to_gray_fixed()
+ Revised example.c, usage of png_destroy_write_struct().
+ Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
+ Added a check for info_ptr->free_me&PNG_FREE_TEXT when freeing text in png.c
+ Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().
+version 1.0.6e [April 9, 2000]
+ Added png_data_freer() function.
+ In the code that checks for over-length tRNS chunks, added check of
+ info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann)
+ Minor revisions of libpng.txt/libpng.3.
+ Check for existing data and free it if the free_me flag is set, in png_set_*()
+ and png_handle_*().
+ Only define PNG_WEIGHTED_FILTERS_SUPPORTED when PNG_FLOATING_POINT_SUPPORTED
+ is defined.
+ Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c
+ and mentioned the purposes of the two macros in libpng.txt/libpng.3.
+version 1.0.6f [April 14, 2000]
+ Revised png_set_iCCP() and png_set_rows() to avoid prematurely freeing data.
+ Add checks in png_set_text() for NULL members of the input text structure.
+ Revised libpng.txt/libpng.3.
+ Removed superfluous prototype for png_set_itxt from png.h
+ Removed "else" from pngread.c, after png_error(), and changed "0" to "length".
+ Changed several png_errors about malformed ancillary chunks to png_warnings.
+version 1.0.6g [April 24, 2000]
+ Added png_pass-* arrays to pnggccrd.c when PNG_USE_LOCAL_ARRAYS is defined.
+ Relocated paragraph about png_set_background() in libpng.3/libpng.txt
+ and other revisions (Matthias Benckmann)
+ Relocated info_ptr->free_me, png_ptr->free_me, and other info_ptr and
+ png_ptr members to restore binary compatibility with libpng-1.0.5
+ (breaks compatibility with libpng-1.0.6).
+version 1.0.6h [April 24, 2000]
+ Changed shared library so-number pattern from 2.x.y.z to xy.z (this builds
+ libpng.so.10 & libpng.so.10.6h instead of libpng.so.2 & libpng.so.2.1.0.6h)
+ This is a temporary change for test purposes.
+version 1.0.6i [May 2, 2000]
+ Rearranged some members at the end of png_info and png_struct, to put
+ unknown_chunks_num and free_me within the original size of the png_structs
+ and free_me, png_read_user_fn, and png_free_fn within the original png_info,
+ because some old applications allocate the structs directly instead of
+ using png_create_*().
+ Added documentation of user memory functions in libpng.txt/libpng.3
+ Modified png_read_png so that it will use user_allocated row_pointers
+ if present, unless free_me directs that it be freed, and added description
+ of the use of png_set_rows() and png_get_rows() in libpng.txt/libpng.3.
+ Added PNG_LEGACY_SUPPORTED macro, and #ifdef out all new (since version
+ 1.00) members of png_struct and png_info, to regain binary compatibility
+ when you define this macro. Capabilities lost in this event
+ are user transforms (new in version 1.0.0),the user transform pointer
+ (new in version 1.0.2), rgb_to_gray (new in 1.0.5), iCCP, sCAL, sPLT,
+ the high-level interface, and unknown chunks support (all new in 1.0.6).
+ This was necessary because of old applications that allocate the structs
+ directly as authors were instructed to do in libpng-0.88 and earlier,
+ instead of using png_create_*().
+ Added modes PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT which
+ can be used to detect codes that directly allocate the structs, and
+ code to check these modes in png_read_init() and png_write_init() and
+ generate a libpng error if the modes aren't set and PNG_LEGACY_SUPPORTED
+ was not defined.
+ Added makefile.intel and updated makefile.watcom (Pawel Mrochen)
+version 1.0.6j [May 3, 2000]
+ Overloaded png_read_init() and png_write_init() with macros that convert
+ calls to png_read_init_2() or png_write_init_2() that check the version
+ and structure sizes.
+version 1.0.7beta11 [May 7, 2000]
+ Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes
+ which are no longer used.
+ Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is
+ defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXT_SUPPORTED
+ is defined.
+ Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory
+ overrun when old applications fill the info_ptr->text structure directly.
+ Added PNGAPI macro, and added it to the definitions of all exported functions.
+ Relocated version macro definitions ahead of the includes of zlib.h and
+ pngconf.h in png.h.
+version 1.0.7beta12 [May 12, 2000]
+ Revised pngset.c to avoid a problem with expanding the png_debug macro.
+ Deleted some extraneous defines from pngconf.h
+ Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined.
+ Use MSC _RPTn debugging instead of fprintf if _MSC_VER is defined.
+ Added png_access_version_number() function.
+ Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data().
+ Expanded libpng.3/libpng.txt information about png_data_freer().
+version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
+ Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as
+ warnings instead of errors, as pngrutil.c does.
+ Set the PNG_INFO_IDAT valid flag in png_set_rows() so png_write_png()
+ will actually write IDATs.
+ Made the default PNG_USE_LOCAL_ARRAYS depend on PNG_DLL instead of WIN32.
+ Make png_free_data() ignore its final parameter except when freeing data
+ that can have multiple instances (text, sPLT, unknowns).
+ Fixed a new bug in png_set_rows().
+ Removed info_ptr->valid tests from png_free_data(), as in version 1.0.5.
+ Added png_set_invalid() function.
+ Fixed incorrect illustrations of png_destroy_write_struct() in example.c.
+version 1.0.7beta15 [May 30, 2000]
+ Revised the deliberately erroneous Linux setjmp code in pngconf.h to produce
+ fewer error messages.
+ Rearranged checks for Z_OK to check the most likely path first in pngpread.c
+ and pngwutil.c.
+ Added checks in pngtest.c for png_create_*() returning NULL, and mentioned
+ in libpng.txt/libpng.3 the need for applications to check this.
+ Changed names of png_default_*() functions in pngtest to pngtest_*().
+ Changed return type of png_get_x|y_offset_*() from png_uint_32 to png_int_32.
+ Fixed some bugs in the unused PNG_INCH_CONVERSIONS functions in pngget.c
+ Set each pointer to NULL after freeing it in png_free_data().
+ Worked around a problem in pngconf.h; AIX's strings.h defines an "index"
+ macro that conflicts with libpng's png_color_16.index. (Dimitri Papadapoulos)
+ Added "msvc" directory with MSVC++ project files (Simon-Pierre Cadieux).
+version 1.0.7beta16 [June 4, 2000]
+ Revised the workaround of AIX string.h "index" bug.
+ Added a check for overlength PLTE chunk in pngrutil.c.
+ Added PNG_NO_POINTER_INDEXING macro to use array-indexing instead of pointer
+ indexing in pngrutil.c and pngwutil.c to accommodate a buggy compiler.
+ Added a warning in png_decompress_chunk() when it runs out of data, e.g.
+ when it tries to read an erroneous PhotoShop iCCP chunk.
+ Added PNG_USE_DLL macro.
+ Revised the copyright/disclaimer/license notice.
+ Added contrib/msvctest directory
+version 1.0.7rc1 [June 9, 2000]
+ Corrected the definition of PNG_TRANSFORM_INVERT_ALPHA (0x0400 not 0x0200)
+ Added contrib/visupng directory (Willem van Schaik)
+version 1.0.7beta18 [June 23, 2000]
+ Revised PNGAPI definition, and pngvcrd.c to work with __GCC__
+ and do not redefine PNGAPI if it is passed in via a compiler directive.
+ Revised visupng/PngFile.c to remove returns from within the Try block.
+ Removed leading underscores from "_PNG_H" and "_PNG_SAVE_BSD_SOURCE" macros.
+ Updated contrib/visupng/cexcept.h to version 1.0.0.
+ Fixed bugs in pngwrite.c and pngwutil.c that prevented writing iCCP chunks.
+version 1.0.7rc2 [June 28, 2000]
+ Updated license to include disclaimers required by UCITA.
+ Fixed "DJBPP" typo in pnggccrd.c introduced in beta18.
+
+version 1.0.7 [July 1, 2000]
+ Revised the definition of "trans_values" in libpng.3/libpng.txt
+version 1.0.8beta1 [July 8, 2000]
+ Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks.
+ Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and
+ pngwutil.c.
+ Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h.
+ Removed unused "#include <assert.h>" from png.c
+ Added WindowsCE support.
+ Revised pnggccrd.c to work with gcc-2.95.2 and in the Cygwin environment.
+version 1.0.8beta2 [July 10, 2000]
+ Added project files to the wince directory and made further revisions
+ of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.
+version 1.0.8beta3 [July 11, 2000]
+ Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS()
+ for indexed-color input files to avoid potential double-freeing trans array
+ under some unusual conditions; problem was introduced in version 1.0.6f.
+ Further revisions to pngtest.c and files in the wince subdirectory.
+version 1.0.8beta4 [July 14, 2000]
+ Added the files pngbar.png and pngbar.jpg to the distribution.
+ Added makefile.cygwin, and cygwin support in pngconf.h
+ Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory)
+version 1.0.8rc1 [July 16, 2000]
+ Revised png_debug() macros and statements to eliminate compiler warnings.
+
+version 1.0.8 [July 24, 2000]
+ Added png_flush() in pngwrite.c, after png_write_IEND().
+ Updated makefile.hpux to build a shared library.
+version 1.0.9beta1 [November 10, 2000]
+ Fixed typo in scripts/makefile.hpux
+ Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
+ Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
+ Changed "cdrom.com" in documentation to "libpng.org"
+ Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg).
+ Changed type of "params" from voidp to png_voidp in png_read|write_png().
+ Make sure PNGAPI and PNG_IMPEXP are defined in pngconf.h.
+ Revised the 3 instances of WRITEFILE in pngtest.c.
+ Relocated "msvc" and "wince" project subdirectories into "dll" subdirectory.
+ Updated png.rc in dll/msvc project
+ Revised makefile.dec to define and use LIBPATH and INCPATH
+ Increased size of global png_libpng_ver[] array from 12 to 18 chars.
+ Made global png_libpng_ver[], png_sig[] and png_pass_*[] arrays const.
+ Removed duplicate png_crc_finish() from png_handle_bKGD() function.
+ Added a warning when application calls png_read_update_info() multiple times.
+ Revised makefile.cygwin
+ Fixed bugs in iCCP support in pngrutil.c and pngwutil.c.
+ Replaced png_set_empty_plte_permitted() with png_permit_mng_features().
+version 1.0.9beta2 [November 19, 2000]
+ Renamed the "dll" subdirectory "projects".
+ Added borland project files to "projects" subdirectory.
+ Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate.
+ Add error message in png_set_compression_buffer_size() when malloc fails.
+version 1.0.9beta3 [November 23, 2000]
+ Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project.
+ Removed the png_flush() in pngwrite.c that crashes some applications
+ that don't set png_output_flush_fn.
+ Added makefile.macosx and makefile.aix to scripts directory.
+version 1.0.9beta4 [December 1, 2000]
+ Change png_chunk_warning to png_warning in png_check_keyword().
+ Increased the first part of msg buffer from 16 to 18 in png_chunk_error().
+version 1.0.9beta5 [December 15, 2000]
+ Added support for filter method 64 (for PNG datastreams embedded in MNG).
+version 1.0.9beta6 [December 18, 2000]
+ Revised png_set_filter() to accept filter method 64 when appropriate.
+ Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to
+ help prevent applications from using MNG features in PNG datastreams.
+ Added png_permit_mng_features() function.
+ Revised libpng.3/libpng.txt. Changed "filter type" to "filter method".
+version 1.0.9rc1 [December 23, 2000]
+ Revised test for PNG_HAVE_PNG_SIGNATURE in pngrutil.c
+ Fixed error handling of unknown compression type in png_decompress_chunk().
+ In pngconf.h, define __cdecl when _MSC_VER is defined.
+version 1.0.9beta7 [December 28, 2000]
+ Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places.
+ Revised memory management in png_set_hIST and png_handle_hIST in a backward
+ compatible manner. PLTE and tRNS were revised similarly.
+ Revised the iCCP chunk reader to ignore trailing garbage.
+version 1.0.9beta8 [January 12, 2001]
+ Moved pngasmrd.h into pngconf.h.
+ Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop.
+version 1.0.9beta9 [January 15, 2001]
+ Added png_set_invalid, png_permit_mng_features, and png_mmx_supported to
+ wince and msvc project module definition files.
+ Minor revision of makefile.cygwin.
+ Fixed bug with progressive reading of narrow interlaced images in pngpread.c
+version 1.0.9beta10 [January 16, 2001]
+ Do not typedef png_FILE_p in pngconf.h when PNG_NO_STDIO is defined.
+ Fixed "png_mmx_supported" typo in project definition files.
+version 1.0.9beta11 [January 19, 2001]
+ Updated makefile.sgi to make shared library.
+ Removed png_mmx_support() function and disabled PNG_MNG_FEATURES_SUPPORTED
+ by default, for the benefit of DLL forward compatibility. These will
+ be re-enabled in version 1.2.0.
+version 1.0.9rc2 [January 22, 2001]
+ Revised cygwin support.
+
+version 1.0.9 [January 31, 2001]
+ Added check of cygwin's ALL_STATIC in pngconf.h
+ Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos.
+version 1.0.10beta1 [March 14, 2001]
+ Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc.
+ Reformatted libpng.3 to eliminate bad line breaks.
+ Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c
+ Added prototype for png_mmx_support() near the top of pnggccrd.c
+ Moved some error checking from png_handle_IHDR to png_set_IHDR.
+ Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros.
+ Revised png_mmx_support() function in pnggccrd.c
+ Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c
+ Fixed memory leak in contrib/visupng/PngFile.c
+ Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version)
+ Added warnings when retrieving or setting gamma=0.
+ Increased the first part of msg buffer from 16 to 18 in png_chunk_warning().
+version 1.0.10rc1 [March 23, 2001]
+ Changed all instances of memcpy, strcpy, and strlen to png_memcpy, png_strcpy,
+ and png_strlen.
+ Revised png_mmx_supported() function in pnggccrd.c to return proper value.
+ Fixed bug in progressive reading (pngpread.c) with small images (height < 8).
+
+version 1.0.10 [March 30, 2001]
+ Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin
+ Added beos project files (Chris Herborth)
+version 1.0.11beta1 [April 3, 2001]
+ Added type casts on several png_malloc() calls (Dimitri Papadapoulos).
+ Removed a no-longer needed AIX work-around from pngconf.h
+ Changed several "//" single-line comments to C-style in pnggccrd.c
+version 1.0.11beta2 [April 11, 2001]
+ Removed PNGAPI from several functions whose prototypes did not have PNGAPI.
+ Updated scripts/pngos2.def
+version 1.0.11beta3 [April 14, 2001]
+ Added checking the results of many instances of png_malloc() for NULL
+version 1.0.11beta4 [April 20, 2001]
+ Undid the changes from version 1.0.11beta3. Added a check for NULL return
+ from user's malloc_fn().
+ Removed some useless type casts of the NULL pointer.
+ Added makefile.netbsd
+
+version 1.0.11 [April 27, 2001]
+ Revised makefile.netbsd
+version 1.0.12beta1 [May 14, 2001]
+ Test for Windows platform in pngconf.h when including malloc.h (Emmanuel Blot)
+ Updated makefile.cygwin and handling of Cygwin's ALL_STATIC in pngconf.h
+ Added some never-to-be-executed code in pnggccrd.c to quiet compiler warnings.
+ Eliminated the png_error about apps using png_read|write_init(). Instead,
+ libpng will reallocate the png_struct and info_struct if they are too small.
+ This retains future binary compatibility for old applications written for
+ libpng-0.88 and earlier.
+version 1.2.0beta1 [May 6, 2001]
+ Bumped DLLNUM to 2.
+ Re-enabled PNG_MNG_FEATURES_SUPPORTED and enabled PNG_ASSEMBLER_CODE_SUPPORTED
+ by default.
+ Added runtime selection of MMX features.
+ Added png_set_strip_error_numbers function and related macros.
+version 1.2.0beta2 [May 7, 2001]
+ Finished merging 1.2.0beta1 with version 1.0.11
+ Added a check for attempts to read or write PLTE in grayscale PNG datastreams.
+version 1.2.0beta3 [May 17, 2001]
+ Enabled user memory function by default.
+ Modified png_create_struct so it passes user mem_ptr to user memory allocator.
+ Increased png_mng_features flag from png_byte to png_uint_32.
+ Bumped shared-library (so-number) and dll-number to 3.
+version 1.2.0beta4 [June 23, 2001]
+ Check for missing profile length field in iCCP chunk and free chunk_data
+ in case of truncated iCCP chunk.
+ Bumped shared-library number to 3 in makefile.sgi and makefile.sggcc
+ Bumped dll-number from 2 to 3 in makefile.cygwin
+ Revised contrib/gregbook/rpng*-x.c to avoid a memory leak and to exit cleanly
+ if user attempts to run it on an 8-bit display.
+ Updated contrib/gregbook
+ Use png_malloc instead of png_zalloc to allocate palette in pngset.c
+ Updated makefile.ibmc
+ Added some typecasts to eliminate gcc 3.0 warnings. Changed prototypes
+ of png_write_oFFS width and height from png_uint_32 to png_int_32.
+ Updated example.c
+ Revised prototypes for png_debug_malloc and png_debug_free in pngtest.c
+version 1.2.0beta5 [August 8, 2001]
+ Revised contrib/gregbook
+ Revised makefile.gcmmx
+ Revised pnggccrd.c to conditionally compile some thread-unsafe code only
+ when PNG_THREAD_UNSAFE_OK is defined.
+ Added tests to prevent pngwutil.c from writing a bKGD or tRNS chunk with
+ value exceeding 2^bit_depth-1
+ Revised makefile.sgi and makefile.sggcc
+ Replaced calls to fprintf(stderr,...) with png_warning() in pnggccrd.c
+ Removed restriction that do_invert_mono only operate on 1-bit opaque files
+
+version 1.2.0 [September 1, 2001]
+ Changed a png_warning() to png_debug() in pnggccrd.c
+ Fixed contrib/gregbook/rpng-x.c, rpng2-x.c to avoid crash with XFreeGC().
+version 1.2.1beta1 [October 19, 2001]
+ Revised makefile.std in contrib/pngminus
+ Include background_1 in png_struct regardless of gamma support.
+ Revised makefile.netbsd and makefile.macosx, added makefile.darwin.
+ Revised example.c to provide more details about using row_callback().
+version 1.2.1beta2 [October 25, 2001]
+ Added type cast to each NULL appearing in a function call, except for
+ WINCE functions.
+ Added makefile.so9.
+version 1.2.1beta3 [October 27, 2001]
+ Removed type casts from all NULLs.
+ Simplified png_create_struct_2().
+version 1.2.1beta4 [November 7, 2001]
+ Revised png_create_info_struct() and png_creat_struct_2().
+ Added error message if png_write_info() was omitted.
+ Type cast NULLs appearing in function calls when _NO_PROTO or
+ PNG_TYPECAST_NULL is defined.
+version 1.2.1rc1 [November 24, 2001]
+ Type cast NULLs appearing in function calls except when PNG_NO_TYPECAST_NULL
+ is defined.
+ Changed typecast of "size" argument to png_size_t in pngmem.c calls to
+ the user malloc_fn, to agree with the prototype in png.h
+ Added a pop/push operation to pnggccrd.c, to preserve Eflag (Maxim Sobolev)
+ Updated makefile.sgi to recognize LIBPATH and INCPATH.
+ Updated various makefiles so "make clean" does not remove previous major
+ version of the shared library.
+version 1.2.1rc2 [December 4, 2001]
+ Always allocate 256-entry internal palette, hist, and trans arrays, to
+ avoid out-of-bounds memory reference caused by invalid PNG datastreams.
+ Added a check for prefix_length > data_length in iCCP chunk handler.
+
+version 1.2.1 [December 7, 2001]
+ None.
+version 1.2.2beta1 [February 22, 2002]
+ Fixed a bug with reading the length of iCCP profiles (Larry Reeves).
+ Revised makefile.linux, makefile.gcmmx, and makefile.sgi to generate
+ libpng.a, libpng12.so (not libpng.so.3), and libpng12/png.h
+ Revised makefile.darwin to remove "-undefined suppress" option.
+ Added checks for gamma and chromaticity values over 21474.83, which exceed
+ the limit for PNG unsigned 32-bit integers when encoded.
+ Revised calls to png_create_read_struct() and png_create_write_struct()
+ for simpler debugging.
+ Revised png_zalloc() so zlib handles errors (uses PNG_FLAG_MALLOC_NULL_MEM_OK)
+version 1.2.2beta2 [February 23, 2002]
+ Check chunk_length and idat_size for invalid (over PNG_MAX_UINT) lengths.
+ Check for invalid image dimensions in png_get_IHDR.
+ Added missing "fi;" in the install target of the SGI makefiles.
+ Added install-static to all makefiles that make shared libraries.
+ Always do gamma compensation when image is partially transparent.
+version 1.2.2beta3 [March 7, 2002]
+ Compute background.gray and background_1.gray even when color_type is RGB
+ in case image gets reduced to gray later.
+ Modified shared-library makefiles to install pkgconfig/libpngNN.pc.
+ Export (with PNGAPI) png_zalloc, png_zfree, and png_handle_as_unknown
+ Removed unused png_write_destroy_info prototype from png.h
+ Eliminated incorrect use of width_mmx from pnggccrd.c in pixel_bytes == 8 case
+ Added install-shared target to all makefiles that make shared libraries.
+ Stopped a double free of palette, hist, and trans when not using free_me.
+ Added makefile.32sunu for Sun Ultra 32 and makefile.64sunu for Sun Ultra 64.
+version 1.2.2beta4 [March 8, 2002]
+ Compute background.gray and background_1.gray even when color_type is RGB
+ in case image gets reduced to gray later (Jason Summers).
+ Relocated a misplaced /bin/rm in the "install-shared" makefile targets
+ Added PNG_1_0_X macro which can be used to build a 1.0.x-compatible library.
+version 1.2.2beta5 [March 26, 2002]
+ Added missing PNGAPI to several function definitions.
+ Check for invalid bit_depth or color_type in png_get_IHDR(), and
+ check for missing PLTE or IHDR in png_push_read_chunk() (Matthias Clasen).
+ Revised iTXt support to accept NULL for lang and lang_key.
+ Compute gamma for color components of background even when color_type is gray.
+ Changed "()" to "{}" in scripts/libpng.pc.in.
+ Revised makefiles to put png.h and pngconf.h only in $prefix/include/libpngNN
+ Revised makefiles to make symlink to libpng.so.NN in addition to libpngNN.so
+version 1.2.2beta6 [March 31, 2002]
+version 1.0.13beta1 [March 31, 2002]
+ Prevent png_zalloc() from trying to memset memory that it failed to acquire.
+ Add typecasts of PNG_MAX_UINT in pngset_cHRM_fixed() (Matt Holgate).
+ Ensure that the right function (user or default) is used to free the
+ png_struct after an error in png_create_read_struct_2().
+version 1.2.2rc1 [April 7, 2002]
+version 1.0.13rc1 [April 7, 2002]
+ Save the ebx register in pnggccrd.c (Sami Farin)
+ Add "mem_ptr = png_ptr->mem_ptr" in png_destroy_write_struct() (Paul Gardner).
+ Updated makefiles to put headers in include/libpng and remove old include/*.h.
+
+version 1.2.2 [April 15, 2002]
+version 1.0.13 [April 15, 2002]
+ Revised description of png_set_filter() in libpng.3/libpng.txt.
+ Revised makefile.netbsd and added makefile.neNNbsd and makefile.freebsd
+version 1.0.13patch01 [April 17, 2002]
+version 1.2.2patch01 [April 17, 2002]
+ Changed ${PNGMAJ}.${PNGVER} bug to ${PNGVER} in makefile.sgi and makefile.sggcc
+ Fixed VER -> PNGVER typo in makefile.macosx and added install-static to install
+ Added install: target to makefile.32sunu and makefile.64sunu
+version 1.0.13patch03 [April 18, 2002]
+version 1.2.2patch03 [April 18, 2002]
+ Revised 15 makefiles to link libpng.a to libpngNN.a and the include libpng
+ subdirectory to libpngNN subdirectory without the full pathname.
+ Moved generation of libpng.pc from "install" to "all" in 15 makefiles.
+version 1.2.3rc1 [April 28, 2002]
+ Added install-man target to 15 makefiles (Dimitri Papadopolous-Orfanos).
+ Added $(DESTDIR) feature to 24 makefiles (Tim Mooney)
+ Fixed bug with $prefix, should be $(prefix) in makefile.hpux.
+ Updated cygwin-specific portion of pngconf.h and revised makefile.cygwin
+ Added a link from libpngNN.pc to libpng.pc in 15 makefiles.
+ Added links from include/libpngNN/*.h to include/*.h in 24 makefiles.
+ Revised makefile.darwin to make relative links without full pathname.
+ Added setjmp() at the end of png_create_*_struct_2() in case user forgets
+ to put one in their application.
+ Restored png_zalloc() and png_zfree() prototypes to version 1.2.1 and
+ removed them from module definition files.
+version 1.2.3rc2 [May 1, 2002]
+ Fixed bug in reporting number of channels in pngget.c and pngset.c,
+ that was introduced in version 1.2.2beta5.
+ Exported png_zalloc(), png_zfree(), png_default_read(), png_default_write(),
+ png_default_flush(), and png_push_fill_buffer() and included them in
+ module definition files.
+ Added "libpng.pc" dependency to the "install-shared" target in 15 makefiles.
+version 1.2.3rc3 [May 1, 2002]
+ Revised prototype for png_default_flush()
+ Remove old libpng.pc and libpngNN.pc before installing new ones.
+version 1.2.3rc4 [May 2, 2002]
+ Typos in *.def files (png_default_read|write -> png_default_read|write_data)
+ In makefiles, changed rm libpng.NN.pc to rm libpngNN.pc
+ Added libpng-config and libpngNN-config and modified makefiles to install them.
+ Changed $(MANPATH) to $(DESTDIR)$(MANPATH) in makefiles
+ Added "Win32 DLL VB" configuration to projects/msvc/libpng.dsp
+version 1.2.3rc5 [May 11, 2002]
+ Changed "error" and "message" in prototypes to "error_message" and
+ "warning_message" to avoid namespace conflict.
+ Revised 15 makefiles to build libpng-config from libpng-config-*.in
+ Once more restored png_zalloc and png_zfree to regular nonexported form.
+ Restored png_default_read|write_data, png_default_flush, png_read_fill_buffer
+ to nonexported form, but with PNGAPI, and removed them from module def files.
+version 1.2.3rc6 [May 14, 2002]
+ Removed "PNGAPI" from png_zalloc() and png_zfree() in png.c
+ Changed "Gz" to "Gd" in projects/msvc/libpng.dsp and zlib.dsp.
+ Removed leftover libpng-config "sed" script from four makefiles.
+ Revised libpng-config creating script in 16 makefiles.
+
+version 1.2.3 [May 22, 2002]
+ Revised libpng-config target in makefile.cygwin.
+ Removed description of png_set_mem_fn() from documentation.
+ Revised makefile.freebsd.
+ Minor cosmetic changes to 15 makefiles, e.g., $(DI) = $(DESTDIR)/$(INCDIR).
+ Revised projects/msvc/README.txt
+ Changed -lpng to -lpngNN in LDFLAGS in several makefiles.
+version 1.2.4beta1 [May 24, 2002]
+ Added libpng.pc and libpng-config to "all:" target in 16 makefiles.
+ Fixed bug in 16 makefiles: $(DESTDIR)/$(LIBPATH) to $(DESTDIR)$(LIBPATH)
+ Added missing "\" before closing double quote in makefile.gcmmx.
+ Plugged various memory leaks; added png_malloc_warn() and png_set_text_2()
+ functions.
+version 1.2.4beta2 [June 25, 2002]
+ Plugged memory leak of png_ptr->current_text (Matt Holgate).
+ Check for buffer overflow before reading CRC in pngpread.c (Warwick Allison)
+ Added -soname to the loader flags in makefile.dec, makefile.sgi, and
+ makefile.sggcc.
+ Added "test-installed" target to makefile.linux, makefile.gcmmx,
+ makefile.sgi, and makefile.sggcc.
+version 1.2.4beta3 [June 28, 2002]
+ Plugged memory leak of row_buf in pngtest.c when there is a png_error().
+ Detect buffer overflow in pngpread.c when IDAT is corrupted with extra data.
+ Added "test-installed" target to makefile.32sunu, makefile.64sunu,
+ makefile.beos, makefile.darwin, makefile.dec, makefile.macosx,
+ makefile.solaris, makefile.hpux, makefile.hpgcc, and makefile.so9.
+version 1.2.4rc1 and 1.0.14rc1 [July 2, 2002]
+ Added "test-installed" target to makefile.cygwin and makefile.sco.
+ Revised pnggccrd.c to be able to back out version 1.0.x via PNG_1_0_X macro.
+
+version 1.2.4 and 1.0.14 [July 8, 2002]
+ Changed png_warning() to png_error() when width is too large to process.
+version 1.2.4patch01 [July 20, 2002]
+ Revised makefile.cygwin to use DLL number 12 instead of 13.
+version 1.2.5beta1 [August 6, 2002]
+ Added code to contrib/gregbook/readpng2.c to ignore unused chunks.
+ Replaced toucan.png in contrib/gregbook (it has been corrupt since 1.0.11)
+ Removed some stray *.o files from contrib/gregbook.
+ Changed png_error() to png_warning() about "Too much data" in pngpread.c
+ and about "Extra compressed data" in pngrutil.c.
+ Prevent png_ptr->pass from exceeding 7 in png_push_finish_row().
+ Updated makefile.hpgcc
+ Updated png.c and pnggccrd.c handling of return from png_mmx_support()
+version 1.2.5beta2 [August 15, 2002]
+ Only issue png_warning() about "Too much data" in pngpread.c when avail_in
+ is nonzero.
+ Updated makefiles to install a separate libpng.so.3 with its own rpath.
+version 1.2.5rc1 and 1.0.15rc1 [August 24, 2002]
+ Revised makefiles to not remove previous minor versions of shared libraries.
+version 1.2.5rc2 and 1.0.15rc2 [September 16, 2002]
+ Revised 13 makefiles to remove "-lz" and "-L$(ZLIBLIB)", etc., from shared
+ library loader directive.
+ Added missing "$OBJSDLL" line to makefile.gcmmx.
+ Added missing "; fi" to makefile.32sunu.
+version 1.2.5rc3 and 1.0.15rc3 [September 18, 2002]
+ Revised libpng-config script.
+
+version 1.2.5 and 1.0.15 [October 3, 2002]
+ Revised makefile.macosx, makefile.darwin, makefile.hpgcc, and makefile.hpux,
+ and makefile.aix.
+ Relocated two misplaced PNGAPI lines in pngtest.c
+version 1.2.6beta1 [October 22, 2002]
+ Commented out warning about uninitialized mmx_support in pnggccrd.c.
+ Changed "IBMCPP__" flag to "__IBMCPP__" in pngconf.h.
+ Relocated two more misplaced PNGAPI lines in pngtest.c
+ Fixed memory overrun bug in png_do_read_filler() with 16-bit datastreams,
+ introduced in version 1.0.2.
+ Revised makefile.macosx, makefile.dec, makefile.aix, and makefile.32sunu.
+version 1.2.6beta2 [November 1, 2002]
+ Added libpng-config "--ldopts" output.
+ Added "AR=ar" and "ARFLAGS=rc" and changed "ar rc" to "$(AR) $(ARFLAGS)"
+ in makefiles.
+version 1.2.6beta3 [July 18, 2004]
+ Reverted makefile changes from version 1.2.6beta2 and some of the changes
+ from version 1.2.6beta1; these will be postponed until version 1.2.7.
+ Version 1.2.6 is going to be a simple bugfix release.
+ Changed the one instance of "ln -sf" to "ln -f -s" in each Sun makefile.
+ Fixed potential overrun in pngerror.c by using strncpy instead of memcpy.
+ Added "#!/bin/sh" at the top of configure, for recognition of the
+ 'x' flag under Cygwin (Cosmin).
+ Optimized vacuous tests that silence compiler warnings, in png.c (Cosmin).
+ Added support for PNG_USER_CONFIG, in pngconf.h (Cosmin).
+ Fixed the special memory handler for Borland C under DOS, in pngmem.c
+ (Cosmin).
+ Removed some spurious assignments in pngrutil.c (Cosmin).
+ Replaced 65536 with 65536L, and 0xffff with 0xffffL, to silence warnings
+ on 16-bit platforms (Cosmin).
+ Enclosed shift op expressions in parentheses, to silence warnings (Cosmin).
+ Used proper type png_fixed_point, to avoid problems on 16-bit platforms,
+ in png_handle_sRGB() (Cosmin).
+ Added compression_type to png_struct, and optimized the window size
+ inside the deflate stream (Cosmin).
+ Fixed definition of isnonalpha(), in pngerror.c and pngrutil.c (Cosmin).
+ Fixed handling of unknown chunks that come after IDAT (Cosmin).
+ Allowed png_error() and png_warning() to work even if png_ptr == NULL
+ (Cosmin).
+ Replaced row_info->rowbytes with row_bytes in png_write_find_filter()
+ (Cosmin).
+ Fixed definition of PNG_LIBPNG_VER_DLLNUM (Simon-Pierre).
+ Used PNG_LIBPNG_VER and PNG_LIBPNG_VER_STRING instead of the hardcoded
+ values in png.c (Simon-Pierre, Cosmin).
+ Initialized png_libpng_ver[] with PNG_LIBPNG_VER_STRING (Simon-Pierre).
+ Replaced PNG_LIBPNG_VER_MAJOR with PNG_LIBPNG_VER_DLLNUM in png.rc
+ (Simon-Pierre).
+ Moved the definition of PNG_HEADER_VERSION_STRING near the definitions
+ of the other PNG_LIBPNG_VER_... symbols in png.h (Cosmin).
+ Relocated #ifndef PNGAPI guards in pngconf.h (Simon-Pierre, Cosmin).
+ Updated scripts/makefile.vc(a)win32 (Cosmin).
+ Updated the MSVC project (Simon-Pierre, Cosmin).
+ Updated the Borland C++ Builder project (Cosmin).
+ Avoided access to asm_flags in pngvcrd.c, if PNG_1_0_X is defined (Cosmin).
+ Commented out warning about uninitialized mmx_support in pngvcrd.c (Cosmin).
+ Removed scripts/makefile.bd32 and scripts/pngdef.pas (Cosmin).
+ Added extra guard around inclusion of Turbo C memory headers, in pngconf.h
+ (Cosmin).
+ Renamed projects/msvc/ to projects/visualc6/, and projects/borland/ to
+ projects/cbuilder5/ (Cosmin).
+ Moved projects/visualc6/png32ms.def to scripts/pngw32.def,
+ and projects/visualc6/png.rc to scripts/pngw32.rc (Cosmin).
+ Added projects/visualc6/pngtest.dsp; removed contrib/msvctest/ (Cosmin).
+ Changed line endings to DOS style in cbuilder5 and visualc6 files, even
+ in the tar.* distributions (Cosmin).
+ Updated contrib/visupng/VisualPng.dsp (Cosmin).
+ Updated contrib/visupng/cexcept.h to version 2.0.0 (Cosmin).
+ Added a separate distribution with "configure" and supporting files (Junichi).
+version 1.2.6beta4 [July 28, 2004]
+ Added user ability to change png_size_t via a PNG_SIZE_T macro.
+ Added png_sizeof() and png_convert_size() functions.
+ Added PNG_SIZE_MAX (maximum value of a png_size_t variable.
+ Added check in png_malloc_default() for (size_t)size != (png_uint_32)size
+ which would indicate an overflow.
+ Changed sPLT failure action from png_error to png_warning and abandon chunk.
+ Changed sCAL and iCCP failures from png_error to png_warning and abandon.
+ Added png_get_uint_31(png_ptr, buf) function.
+ Added PNG_UINT_32_MAX macro.
+ Renamed PNG_MAX_UINT to PNG_UINT_31_MAX.
+ Made png_zalloc() issue a png_warning and return NULL on potential
+ overflow.
+ Turn on PNG_NO_ZALLOC_ZERO by default in version 1.2.x
+ Revised "clobber list" in pnggccrd.c so it will compile under gcc-3.4.
+ Revised Borland portion of png_malloc() to return NULL or issue
+ png_error() according to setting of PNG_FLAG_MALLOC_NULL_MEM_OK.
+ Added PNG_NO_SEQUENTIAL_READ_SUPPORTED macro to conditionally remove
+ sequential read support.
+ Added some "#if PNG_WRITE_SUPPORTED" blocks.
+ Added #ifdef to remove some redundancy in png_malloc_default().
+ Use png_malloc instead of png_zalloc to allocate the pallete.
+version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
+ Fixed buffer overflow vulnerability in png_handle_tRNS()
+ Fixed integer arithmetic overflow vulnerability in png_read_png().
+ Fixed some harmless bugs in png_handle_sBIT, etc, that would cause
+ duplicate chunk types to go undetected.
+ Fixed some timestamps in the -config version
+ Rearranged order of processing of color types in png_handle_tRNS().
+ Added ROWBYTES macro to calculate rowbytes without integer overflow.
+ Updated makefile.darwin and removed makefile.macosx from scripts directory.
+ Imposed default one million column, one-million row limits on the image
+ dimensions, and added png_set_user_limits() function to override them.
+ Revised use of PNG_SET_USER_LIMITS_SUPPORTED macro.
+ Fixed wrong cast of returns from png_get_user_width|height_max().
+ Changed some "keep the compiler happy" from empty statements to returns,
+ Revised libpng.txt to remove 1.2.x stuff from the 1.0.x distribution
+version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004]
+ Revised makefile.darwin and makefile.solaris. Removed makefile.macosx.
+ Revised pngtest's png_debug_malloc() to use png_malloc() instead of
+ png_malloc_default() which is not supposed to be exported.
+ Fixed off-by-one error in one of the conversions to PNG_ROWBYTES() in
+ pngpread.c. Bug was introduced in 1.2.6rc1.
+ Fixed bug in RGB to RGBX transformation introduced in 1.2.6rc1.
+ Fixed old bug in RGB to Gray transformation.
+ Fixed problem with 64-bit compilers by casting arguments to abs()
+ to png_int_32.
+ Changed "ln -sf" to "ln -f -s" in three makefiles (solaris, sco, so9).
+ Changed "HANDLE_CHUNK_*" to "PNG_HANDLE_CHUNK_*" (Cosmin)
+ Added "-@/bin/rm -f $(DL)/$(LIBNAME).so.$(PNGMAJ)" to 15 *NIX makefiles.
+ Added code to update the row_info->colortype in png_do_read_filler() (MSB).
+version 1.0.16rc3 and 1.2.6rc3 [August 9, 2004]
+ Eliminated use of "abs()" in testing cHRM and gAMA values, to avoid
+ trouble with some 64-bit compilers. Created PNG_OUT_OF_RANGE() macro.
+ Revised documentation of png_set_keep_unknown_chunks().
+ Check handle_as_unknown status in pngpread.c, as in pngread.c previously.
+ Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_INTERNAL section of png.h
+ Added "rim" definitions for CONST4 and CONST6 in pnggccrd.c
+version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004]
+ Fixed mistake in pngtest.c introduced in 1.2.6rc2 (declaration of
+ "pinfo" was out of place).
+version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004]
+ Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED
+ section of png.h where they were inadvertently placed in version rc3.
+
+version 1.2.6 and 1.0.16 [August 15, 2004]
+ Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1.
+version 1.2.7beta1 [August 26, 2004]
+ Removed unused pngasmrd.h file.
+ Removed references to uu.net for archived files. Added references to
+ PNG Spec (second edition) and the PNG ISO/IEC Standard.
+ Added "test-dd" target in 15 makefiles, to run pngtest in DESTDIR.
+ Fixed bug with "optimized window size" in the IDAT datastream, that
+ causes libpng to write PNG files with incorrect zlib header bytes.
+version 1.2.7beta2 [August 28, 2004]
+ Fixed bug with sCAL chunk and big-endian machines (David Munro).
+ Undid new code added in 1.2.6rc2 to update the color_type in
+ png_set_filler().
+ Added png_set_add_alpha() that updates color type.
+version 1.0.17rc1 and 1.2.7rc1 [September 4, 2004]
+ Revised png_set_strip_filler() to not remove alpha if color_type has alpha.
+
+version 1.2.7 and 1.0.17 [September 12, 2004]
+ Added makefile.hp64
+ Changed projects/msvc/png32ms.def to scripts/png32ms.def in makefile.cygwin
+version 1.2.8beta1 [November 1, 2004]
+ Fixed bug in png_text_compress() that would fail to complete a large block.
+ Fixed bug, introduced in libpng-1.2.7, that overruns a buffer during
+ strip alpha operation in png_do_strip_filler().
+ Added PNG_1_2_X definition in pngconf.h
+ Use #ifdef to comment out png_info_init in png.c and png_read_init in
+ pngread.c (as of 1.3.0)
+version 1.2.8beta2 [November 2, 2004]
+ Reduce color_type to a nonalpha type after strip alpha operation in
+ png_do_strip_filler().
+version 1.2.8beta3 [November 3, 2004]
+ Revised definitions of PNG_MAX_UINT_32, PNG_MAX_SIZE, and PNG_MAXSUM
+version 1.2.8beta4 [November 12, 2004]
+ Fixed (again) definition of PNG_LIBPNG_VER_DLLNUM in png.h (Cosmin).
+ Added PNG_LIBPNG_BUILD_PRIVATE in png.h (Cosmin).
+ Set png_ptr->zstream.data_type to Z_BINARY, to avoid unnecessary detection
+ of data type in deflate (Cosmin).
+ Deprecated but continue to support SPECIALBUILD and PRIVATEBUILD in favor of
+ PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
+version 1.2.8beta5 [November 20, 2004]
+ Use png_ptr->flags instead of png_ptr->transformations to pass
+ PNG_STRIP_ALPHA info to png_do_strip_filler(), to preserve ABI
+ compatibility.
+ Revised handling of SPECIALBUILD, PRIVATEBUILD,
+ PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
+version 1.2.8rc1 [November 24, 2004]
+ Moved handling of BUILD macros from pngconf.h to png.h
+ Added definition of PNG_LIBPNG_BASE_TYPE in png.h, inadvertently
+ omitted from beta5.
+ Revised scripts/pngw32.rc
+ Despammed mailing addresses by masking "@" with "at".
+ Inadvertently installed a supposedly faster test version of pngrutil.c
+version 1.2.8rc2 [November 26, 2004]
+ Added two missing "\" in png.h
+ Change tests in pngread.c and pngpread.c to
+ if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
+ png_do_read_transformations(png_ptr);
+version 1.2.8rc3 [November 28, 2004]
+ Reverted pngrutil.c to version libpng-1.2.8beta5.
+ Added scripts/makefile.elf with supporting code in pngconf.h for symbol
+ versioning (John Bowler).
+version 1.2.8rc4 [November 29, 2004]
+ Added projects/visualc7 (Simon-pierre).
+version 1.2.8rc5 [November 29, 2004]
+ Fixed new typo in scripts/pngw32.rc
+
+version 1.2.8 [December 3, 2004]
+ Removed projects/visualc7, added projects/visualc71.
+
+version 1.2.9beta1 [February 21, 2006]
+
+ Initialized some structure members in pngwutil.c to avoid gcc-4.0.0 complaints
+ Revised man page and libpng.txt to make it clear that one should not call
+ png_read_end or png_write_end after png_read_png or png_write_png.
+ Updated references to png-mng-implement mailing list.
+ Fixed an incorrect typecast in pngrutil.c
+ Added PNG_NO_READ_SUPPORTED conditional for making a write-only library.
+ Added PNG_NO_WRITE_INTERLACING_SUPPORTED conditional.
+ Optimized alpha-inversion loops in pngwtran.c
+ Moved test for nonzero gamma outside of png_build_gamma_table() in pngrtran.c
+ Make sure num_trans is <= 256 before copying data in png_set_tRNS().
+ Make sure num_palette is <= 256 before copying data in png_set_PLTE().
+ Interchanged order of write_swap_alpha and write_invert_alpha transforms.
+ Added parentheses in the definition of PNG_LIBPNG_BUILD_TYPE (Cosmin).
+ Optimized zlib window flag (CINFO) in contrib/pngsuite/*.png (Cosmin).
+ Updated scripts/makefile.bc32 for Borland C++ 5.6 (Cosmin).
+ Exported png_get_uint_32, png_save_uint_32, png_get_uint_16, png_save_uint_16,
+ png_get_int_32, png_save_int_32, png_get_uint_31 (Cosmin).
+ Added type cast (png_byte) in png_write_sCAL() (Cosmin).
+ Fixed scripts/makefile.cygwin (Christian Biesinger, Cosmin).
+ Default iTXt support was inadvertently enabled.
+
+version 1.2.9beta2 [February 21, 2006]
+
+ Check for png_rgb_to_gray and png_gray_to_rgb read transformations before
+ checking for png_read_dither in pngrtran.c
+ Revised checking of chromaticity limits to accommodate extended RGB
+ colorspace (John Denker).
+ Changed line endings in some of the project files to CRLF, even in the
+ "Unix" tar distributions (Cosmin).
+ Made png_get_int_32 and png_save_int_32 always available (Cosmin).
+ Updated scripts/pngos2.def, scripts/pngw32.def and projects/wince/png32ce.def
+ with the newly exported functions.
+ Eliminated distributions without the "configure" script.
+ Updated INSTALL instructions.
+
+version 1.2.9beta3 [February 24, 2006]
+
+ Fixed CRCRLF line endings in contrib/visupng/VisualPng.dsp
+ Made libpng.pc respect EXEC_PREFIX (D. P. Kreil, J. Bowler)
+ Removed reference to pngasmrd.h from Makefile.am
+ Renamed CHANGES to ChangeLog.
+ Renamed LICENSE to COPYING.
+ Renamed ANNOUNCE to NEWS.
+ Created AUTHORS file.
+
+version 1.2.9beta4 [March 3, 2006]
+
+ Changed definition of PKGCONFIG from $prefix/lib to $libdir in configure.ac
+ Reverted to filenames LICENSE and ANNOUNCE; removed AUTHORS and COPYING.
+ Removed newline from the end of some error and warning messages.
+ Removed test for sqrt() from configure.ac and configure.
+ Made swap tables in pngtrans.c PNG_CONST (Carlo Bramix).
+ Disabled default iTXt support that was inadvertently enabled in
+ libpng-1.2.9beta1.
+ Added "OS2" to list of systems that don't need underscores, in pnggccrd.c
+ Removed libpng version and date from *.c files.
+
+version 1.2.9beta5 [March 4, 2006]
+ Removed trailing blanks from source files.
+ Put version and date of latest change in each source file, and changed
+ copyright year accordingly.
+ More cleanup of configure.ac, Makefile.ac, and associated scripts.
+ Restored scripts/makefile.elf which was inadvertently deleted.
+
+version 1.2.9beta6 [March 6, 2006]
+ Fixed typo (RELEASE) in configuration files.
+
+version 1.2.9beta7 [March 7, 2006]
+ Removed libpng.vers and libpng.sym from libpng12_la_SOURCES in Makefile.am
+ Fixed inconsistent #ifdef's around png_sig_bytes() and png_set_sCAL_s()
+ in png.h.
+ Updated makefile.elf as suggested by debian.
+ Made cosmetic changes to some makefiles, adding LN_SF and other macros.
+ Made some makefiles accept "exec_prefix".
+
+version 1.2.9beta8 [March 9, 2006]
+ Fixed some "#if defined (..." which should be "#if defined(..."
+ Bug introduced in libpng-1.2.8.
+ Fixed inconsistency in definition of png_default_read_data()
+ Restored blank that was lost from makefile.sggcc "clean" target in beta7.
+ Revised calculation of "current" and "major" for irix in ltmain.sh
+ Changed "mkdir" to "MKDIR_P" in some makefiles.
+ Separated PNG_EXPAND and PNG_EXPAND_tRNS.
+ Added png_set_expand_gray_1_2_4_to_8() and deprecated
+ png_set_gray_1_2_4_to_8() which also expands tRNS to alpha.
+
+version 1.2.9beta9 [March 10, 2006]
+ Include "config.h" in pngconf.h when available.
+ Added some checks for NULL png_ptr or NULL info_ptr (timeless)
+
+version 1.2.9beta10 [March 20, 2006]
+ Removed extra CR from contrib/visualpng/VisualPng.dsw (Cosmin)
+ Made pnggccrd.c PIC-compliant (Christian Aichinger).
+ Added makefile.mingw (Wolfgang Glas).
+ Revised pngconf.h MMX checking.
+
+version 1.2.9beta11 [March 22, 2006]
+ Fixed out-of-order declaration in pngwrite.c that was introduced in beta9
+ Simplified some makefiles by using LIBSO, LIBSOMAJ, and LIBSOVER macros.
+
+version 1.2.9rc1 [March 31, 2006]
+ Defined PNG_USER_PRIVATEBUILD when including "pngusr.h" (Cosmin).
+ Removed nonsensical assertion check from pngtest.c (Cosmin).
+
+version 1.2.9 [April 14, 2006]
+ Revised makefile.beos and added "none" selector in ltmain.sh
+
+version 1.2.10beta1 [April 15, 2006]
+ Renamed "config.h" to "png_conf.h" and revised Makefile.am to add
+ -DPNG_BUILDING_LIBPNG to compile directive, and modified pngconf.h
+ to include png_conf.h only when PNG_BUILDING_LIBPNG is defined.
+
+version 1.2.10beta2 [April 15, 2006]
+ Manually updated Makefile.in and configure. Changed png_conf.h.in
+ back to config.h.
+
+version 1.2.10beta3 [April 15, 2006]
+ Change png_conf.h back to config.h in pngconf.h.
+
+version 1.2.10beta4 [April 16, 2006]
+ Change PNG_BUILDING_LIBPNG to PNG_CONFIGURE_LIBPNG in config/Makefile*.
+
+version 1.2.10beta5 [April 16, 2006]
+ Added a configure check for compiling assembler code in pnggccrd.c
+
+version 1.2.10beta6 [April 17, 2006]
+ Revised the configure check for pnggccrd.c
+ Moved -DPNG_CONFIGURE_LIBPNG into @LIBPNG_DEFINES@
+ Added @LIBPNG_DEFINES@ to arguments when building libpng.sym
+
+version 1.2.10beta7 [April 18, 2006]
+ Change "exec_prefix=$prefix" to "exec_prefix=$(prefix)" in makefiles.
+
+version 1.2.10rc1 [April 19, 2006]
+ Ensure pngconf.h doesn't define both PNG_USE_PNGGCCRD and PNG_USE_PNGVCRD
+ Fixed "LN_FS" typo in makefile.sco and makefile.solaris.
+
+version 1.2.10rc2 [April 20, 2006]
+ Added a backslash between -DPNG_CONFIGURE_LIBPNG and -DPNG_NO_ASSEMBLER_CODE
+ in configure.ac and configure
+ Made the configure warning about versioned symbols less arrogant.
+
+version 1.2.10rc3 [April 21, 2006]
+ Added a note in libpng.txt that png_set_sig_bytes(8) can be used when
+ writing an embedded PNG without the 8-byte signature.
+ Revised makefiles and configure to avoid making links to libpng.so.*
+
+version 1.2.10 [April 23, 2006]
+ Reverted configure to "rc2" state.
+
+version 1.2.11beta1 [May 31, 2006]
+ scripts/libpng.pc.in contained "configure" style version info and would
+ not work with makefiles.
+ The shared-library makefiles were linking to libpng.so.0 instead of
+ libpng.so.3 compatibility as the library.
+
+version 1.2.11beta2 [June 2, 2006]
+ Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
+ buffer overflow.
+ Fixed bug in example.c (png_set_palette_rgb -> png_set_palette_to_rgb)
+
+version 1.2.11beta3 [June 5, 2006]
+ Prepended "#! /bin/sh" to ltmail.sh and contrib/pngminus/*.sh (Cosmin).
+ Removed the accidental leftover Makefile.in~ (Cosmin).
+ Avoided potential buffer overflow and optimized buffer in
+ png_write_sCAL(), png_write_sCAL_s() (Cosmin).
+ Removed the include directories and libraries from CFLAGS and LDFLAGS
+ in scripts/makefile.gcc (Nelson A. de Oliveira, Cosmin).
+
+version 1.2.11beta4 [June 6, 2006]
+ Allow zero-length IDAT chunks after the entire zlib datastream, but not
+ after another intervening chunk type.
+
+version 1.0.19rc1, 1.2.11rc1 [June 13, 2006]
+ Deleted extraneous square brackets from [config.h] in configure.ac
+
+version 1.0.19rc2, 1.2.11rc2 [June 14, 2006]
+ Added prototypes for PNG_INCH_CONVERSIONS functions to png.h
+ Revised INSTALL and autogen.sh
+ Fixed typo in several makefiles (-W1 should be -Wl)
+ Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
+
+version 1.0.19rc3, 1.2.11rc3 [June 15, 2006]
+ Removed the new typedefs for 64-bit systems (delay until version 1.4.0)
+ Added one zero element to png_gamma_shift[] array in pngrtran.c to avoid
+ reading out of bounds.
+
+version 1.0.19rc4, 1.2.11rc4 [June 15, 2006]
+ Really removed the new typedefs for 64-bit systems.
+
+version 1.0.19rc5, 1.2.11rc5 [June 22, 2006]
+ Removed png_sig_bytes entry from scripts/pngw32.def
+
+version 1.0.19, 1.2.11 [June 26, 2006]
+ None.
+
+version 1.0.20, 1.2.12 [June 27, 2006]
+ Really increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
+ buffer overflow.
+
+version 1.2.13beta1 [October 2, 2006]
+ Removed AC_FUNC_MALLOC from configure.ac
+ Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
+ Change "logical" to "bitwise" throughout documentation.
+ Detect and fix attempt to write wrong iCCP profile length.
+
+version 1.0.21, 1.2.13 [November 14, 2006]
+ Fix potential buffer overflow in sPLT chunk handler.
+ Fix Makefile.am to not try to link to noexistent files.
+ Check all exported functions for NULL png_ptr.
+
+version 1.2.14beta1 [November 17, 2006]
+ Relocated three misplaced tests for NULL png_ptr.
+ Built Makefile.in with automake-1.9.6 instead of 1.9.2.
+ Build configure with autoconf-2.60 instead of 2.59
+
+version 1.2.14beta2 [November 17, 2006]
+ Added some typecasts in png_zalloc().
+
+version 1.2.14rc1 [November 20, 2006]
+ Changed "strtod" to "png_strtod" in pngrutil.c
+
+version 1.0.22, 1.2.14 [November 27, 2006]
+ Added missing "$(srcdir)" in Makefile.am and Makefile.in
+
+version 1.2.15beta1 [December 3, 2006]
+ Generated configure with autoconf-2.61 instead of 2.60
+ Revised configure.ac to update libpng.pc and libpng-config.
+
+version 1.2.15beta2 [December 3, 2006]
+ Always export MMX asm functions, just stubs if not building pnggccrd.c
+
+version 1.2.15beta3 [December 4, 2006]
+ Add "png_bytep" typecast to profile while calculating length in pngwutil.c
+
+version 1.2.15beta4 [December 7, 2006]
+ Added scripts/CMakeLists.txt
+ Changed PNG_NO_ASSEMBLER_CODE to PNG_NO_MMX_CODE in scripts, like 1.4.0beta
+
+version 1.2.15beta5 [December 7, 2006]
+ Changed some instances of PNG_ASSEMBLER_* to PNG_MMX_* in pnggccrd.c
+ Revised scripts/CMakeLists.txt
+
+version 1.2.15beta6 [December 13, 2006]
+ Revised scripts/CMakeLists.txt and configure.ac
+
+version 1.2.15rc1 [December 18, 2006]
+ Revised scripts/CMakeLists.txt
+
+version 1.2.15rc2 [December 21, 2006]
+ Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
+ Added scripts/makefile.nommx
+
+version 1.2.15rc3 [December 25, 2006]
+ Fixed shared library numbering error that was introduced in 1.2.15beta6.
+
+version 1.2.15rc4 [December 27, 2006]
+ Fixed handling of rgb_to_gray when png_ptr->color.gray isn't set.
+
+version 1.2.15rc5 [December 31, 2006]
+ Revised handling of rgb_to_gray.
+
+version 1.2.15 [January 5, 2007]
+ Added some (unsigned long) typecasts in pngtest.c to avoid printing errors.
+
+version 1.2.16beta1 [January 6, 2007]
+ Fix bugs in makefile.nommx
+
+version 1.2.16beta2 [January 16, 2007]
+ Revised scripts/CMakeLists.txt
+
+version 1.2.16 [January 31, 2007]
+ No changes.
+
+version 1.2.17beta1 [March 6, 2007]
+ Revised scripts/CMakeLists.txt to install both shared and static libraries.
+ Deleted a redundant line from pngset.c.
+
+version 1.2.17beta2 [April 26, 2007]
+ Relocated misplaced test for png_ptr == NULL in pngpread.c
+ Change "==" to "&" for testing PNG_RGB_TO_GRAY_ERR & PNG_RGB_TO_GRAY_WARN
+ flags.
+ Changed remaining instances of PNG_ASSEMBLER_* to PNG_MMX_*
+ Added pngerror() when write_IHDR fails in deflateInit2().
+ Added "const" to some array declarations.
+ Mention examples of libpng usage in the libpng*.txt and libpng.3 documents.
+
+version 1.2.17rc1 [May 4, 2007]
+ No changes.
+
+version 1.2.17rc2 [May 8, 2007]
+ Moved several PNG_HAVE_* macros out of PNG_INTERNAL because applications
+ calling set_unknown_chunk_location() need them.
+ Changed transformation flag from PNG_EXPAND_tRNS to PNG_EXPAND in
+ png_set_expand_gray_1_2_4_to_8().
+ Added png_ptr->unknown_chunk to hold working unknown chunk data, so it
+ can be free'ed in case of error. Revised unknown chunk handling in
+ pngrutil.c and pngpread.c to use this structure.
+
+version 1.2.17rc3 [May 8, 2007]
+ Revised symbol-handling in configure script.
+
+version 1.2.17rc4 [May 10, 2007]
+ Revised unknown chunk handling to avoid storing unknown critical chunks.
+
+version 1.0.25 [May 15, 2007]
+version 1.2.17 [May 15, 2007]
+ Added "png_ptr->num_trans=0" before error return in png_handle_tRNS,
+ to eliminate a vulnerability (CVE-2007-2445, CERT VU#684664)
+
+version 1.0.26 [May 15, 2007]
+version 1.2.18 [May 15, 2007]
+ Reverted the libpng-1.2.17rc3 change to symbol-handling in configure script
+
+version 1.2.19beta1 [May 18, 2007]
+ Changed "const static" to "static PNG_CONST" everywhere, mostly undoing
+ change of libpng-1.2.17beta2. Changed other "const" to "PNG_CONST"
+ Changed some handling of unused parameters, to avoid compiler warnings.
+ "if (unused == NULL) return;" becomes "unused = unused".
+
+version 1.2.19beta2 [May 18, 2007]
+ Only use the valid bits of tRNS value in png_do_expand() (Brian Cartier)
+
+version 1.2.19beta3 [May 19, 2007]
+ Add some "png_byte" typecasts in png_check_keyword() and write new_key
+ instead of key in zTXt chunk (Kevin Ryde).
+
+version 1.2.19beta4 [May 21, 2007]
+ Add png_snprintf() function and use it in place of sprint() for improved
+ defense against buffer overflows.
+
+version 1.2.19beta5 [May 21, 2007]
+ Fixed png_handle_tRNS() to only use the valid bits of tRNS value.
+ Changed handling of more unused parameters, to avoid compiler warnings.
+ Removed some PNG_CONST in pngwutil.c to avoid compiler warnings.
+
+version 1.2.19beta6 [May 22, 2007]
+ Added some #ifdef PNG_MMX_CODE_SUPPORTED where needed in pngvcrd.c
+ Added a special "_MSC_VER" case that defines png_snprintf to _snprintf
+
+version 1.2.19beta7 [May 22, 2007]
+ Squelched png_squelch_warnings() in pnggccrd.c and added
+ an #ifdef PNG_MMX_CODE_SUPPORTED block around the declarations that caused
+ the warnings that png_squelch_warnings was squelching.
+
+version 1.2.19beta8 [May 22, 2007]
+ Removed __MMX__ from test in pngconf.h.
+
+version 1.2.19beta9 [May 23, 2007]
+ Made png_squelch_warnings() available via PNG_SQUELCH_WARNINGS macro.
+ Revised png_squelch_warnings() so it might work.
+ Updated makefile.sgcc and makefile.solaris; added makefile.solaris-x86.
+
+version 1.2.19beta10 [May 24, 2007]
+ Resquelched png_squelch_warnings(), use "__attribute__((used))" instead.
+
+version 1.4.0beta1 [April 20, 2006]
+ Enabled iTXt support (changes png_struct, thus requires so-number change).
+ Cleaned up PNG_ASSEMBLER_CODE_SUPPORTED vs PNG_MMX_CODE_SUPPORTED
+ Eliminated PNG_1_0_X and PNG_1_2_X macros.
+ Removed deprecated functions png_read_init, png_write_init, png_info_init,
+ png_permit_empty_plte, png_set_gray_1_2_4_to_8, png_check_sig, and
+ removed the deprecated macro PNG_MAX_UINT.
+ Moved "PNG_INTERNAL" parts of png.h and pngconf.h into pngintrn.h
+ Removed many WIN32_WCE #ifdefs (Cosmin).
+ Reduced dependency on C-runtime library when on Windows (Simon-Pierre)
+ Replaced sprintf() with png_sprintf() (Simon-Pierre)
+
+version 1.4.0beta2 [April 20, 2006]
+ Revised makefiles and configure to avoid making links to libpng.so.*
+ Moved some leftover MMX-related defines from pngconf.h to pngintrn.h
+ Updated scripts/pngos2.def, pngw32.def, and projects/wince/png32ce.def
+
+version 1.4.0beta3 [May 10, 2006]
+ Updated scripts/pngw32.def to comment out MMX functions.
+ Added PNG_NO_GET_INT_32 and PNG_NO_SAVE_INT_32 macros.
+ Scripts/libpng.pc.in contained "configure" style version info and would
+ not work with makefiles.
+ Revised pngconf.h and added pngconf.h.in, so makefiles and configure can
+ pass defines to libpng and applications.
+
+version 1.4.0beta4 [May 11, 2006]
+ Revised configure.ac, Makefile.am, and many of the makefiles to write
+ their defines in pngconf.h.
+
+version 1.4.0beta5 [May 15, 2006]
+ Added a missing semicolon in Makefile.am and Makefile.in
+ Deleted extraneous square brackets from configure.ac
+
+version 1.4.0beta6 [June 2, 2006]
+ Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
+ buffer overflow.
+ Changed sonum from 0 to 1.
+ Removed unused prototype for png_check_sig() from png.h
+
+version 1.4.0beta7 [June 16, 2006]
+ Exported png_write_sig (Cosmin).
+ Optimized buffer in png_handle_cHRM() (Cosmin).
+ Set pHYs = 2835 x 2835 pixels per meter, and added
+ sCAL = 0.352778e-3 x 0.352778e-3 meters, in pngtest.png (Cosmin).
+ Added png_set_benign_errors(), png_benign_error(), png_chunk_benign_error().
+ Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
+ Added "(unsigned long)" typecast on png_uint_32 variables in printf lists.
+
+version 1.4.0beta8 [June 22, 2006]
+ Added demonstration of user chunk support in pngtest.c, to support the
+ public sTER chunk and a private vpAg chunk.
+
+version 1.4.0beta9 [July 3, 2006]
+ Removed ordinals from scripts/pngw32.def and removed png_info_int and
+ png_set_gray_1_2_4_to_8 entries.
+ Inline call of png_get_uint_32() in png_get_uint_31().
+ Use png_get_uint_31() to get vpAg width and height in pngtest.c
+ Removed WINCE and Netware projects.
+ Removed standalone Y2KINFO file.
+
+version 1.4.0beta10 [July 12, 2006]
+ Eliminated automatic copy of pngconf.h to pngconf.h.in from configure and
+ some makefiles, because it was not working reliably. Instead, distribute
+ pngconf.h.in along with pngconf.h and cause configure and some of the
+ makefiles to update pngconf.h from pngconf.h.in.
+ Added pngconf.h to DEPENDENCIES in Makefile.am
+
+version 1.4.0beta11 [August 19, 2006]
+ Removed AC_FUNC_MALLOC from configure.ac.
+ Added a warning when writing iCCP profile with mismatched profile length.
+ Patched pnggccrd.c to assemble on x86_64 platforms.
+ Moved chunk header reading into a separate function png_read_chunk_header()
+ in pngrutil.c. The chunk header (len+sig) is now serialized in a single
+ operation (Cosmin).
+ Implemented support for I/O states. Added png_ptr member io_state, and
+ functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
+ (Cosmin).
+ Added png_get_io_chunk_name and png_get_io_state to scripts/*.def (Cosmin).
+ Renamed scripts/pngw32.* to scripts/pngwin.* (Cosmin).
+ Removed the include directories and libraries from CFLAGS and LDFLAGS
+ in scripts/makefile.gcc (Cosmin).
+ Used png_save_uint_32() to set vpAg width and height in pngtest.c (Cosmin).
+ Cast to proper type when getting/setting vpAg units in pngtest.c (Cosmin).
+ Added pngintrn.h to the Visual C++ projects (Cosmin).
+ Removed scripts/list (Cosmin).
+ Updated copyright year in scripts/pngwin.def (Cosmin).
+ Removed PNG_TYPECAST_NULL and used standard NULL consistently (Cosmin).
+ Disallowed the user to redefine png_size_t, and enforced a consistent use
+ of png_size_t across libpng (Cosmin).
+ Changed the type of png_ptr->rowbytes, PNG_ROWBYTES() and friends
+ to png_size_t (Cosmin).
+ Removed png_convert_size() and replaced png_sizeof with sizeof (Cosmin).
+ Removed some unnecessary type casts (Cosmin).
+ Changed prototype of png_get_compression_buffer_size() and
+ png_set_compression_buffer_size() to work with png_size_t instead of
+ png_uint_32 (Cosmin).
+ Removed png_memcpy_check() and png_memset_check() (Cosmin).
+ Fixed a typo (png_byte --> png_bytep) in libpng.3 and libpng.txt (Cosmin).
+ Clarified that png_zalloc() does not clear the allocated memory,
+ and png_zalloc() and png_zfree() cannot be PNGAPI (Cosmin).
+ Renamed png_mem_size_t to png_alloc_size_t, fixed its definition in
+ pngconf.h, and used it in all memory allocation functions (Cosmin).
+ Renamed pngintrn.h to pngpriv.h, added a comment at the top of the file
+ mentioning that the symbols declared in that file are private, and
+ updated the scripts and the Visual C++ projects accordingly (Cosmin).
+ Removed circular references between pngconf.h and pngconf.h.in in
+ scripts/makefile.vc*win32 (Cosmin).
+ Removing trailing '.' from the warning and error messages (Cosmin).
+ Added pngdefs.h that is built by makefile or configure, instead of
+ pngconf.h.in (Glenn).
+ Detect and fix attempt to write wrong iCCP profile length.
+
+version 1.4.0beta12 [October 19, 2006]
+ Changed "logical" to "bitwise" in the documentation.
+ Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
+ Add a typecast to stifle compiler warning in pngrutil.c
+
+version 1.4.0beta13 [November 10, 2006]
+ Fix potential buffer overflow in sPLT chunk handler.
+ Fix Makefile.am to not try to link to noexistent files.
+
+version 1.4.0beta14 [November 15, 2006]
+ Check all exported functions for NULL png_ptr.
+
+version 1.4.0beta15 [November 17, 2006]
+ Relocated two misplaced tests for NULL png_ptr.
+ Built Makefile.in with automake-1.9.6 instead of 1.9.2.
+ Build configure with autoconf-2.60 instead of 2.59
+ Add "install: all" in Makefile.am so "configure; make install" will work.
+
+version 1.4.0beta16 [November 17, 2006]
+ Added a typecast in png_zalloc().
+
+version 1.4.0beta17 [December 4, 2006]
+ Changed "new_key[79] = '\0';" to "(*new_key)[79] = '\0';" in pngwutil.c
+ Add "png_bytep" typecast to profile while calculating length in pngwutil.c
+
+version 1.4.0beta18 [December 7, 2006]
+ Added scripts/CMakeLists.txt
+
+version 1.4.0beta19 [May 16, 2007]
+ Revised scripts/CMakeLists.txt
+ Rebuilt configure and Makefile.in with newer tools.
+ Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
+ Added scripts/makefile.nommx
+
+version 1.4.0beta20 [July 9, 2008]
+ Moved several PNG_HAVE_* macros from pngpriv.h to png.h because applications
+ calling set_unknown_chunk_location() need them.
+ Moved several macro definitions from pngpriv.h to pngconf.h
+ Merge with changes to the 1.2.X branch, as of 1.2.30beta04.
+ Deleted all use of the MMX assembler code and Intel-licensed optimizations.
+ Revised makefile.mingw
+
+version 1.4.0beta21 [July 21, 2008]
+ Moved local array "chunkdata" from pngrutil.c to the png_struct, so
+ it will be freed by png_read_destroy() in case of a read error (Kurt
+ Christensen).
+
+version 1.4.0beta22 [July 21, 2008]
+ Change "purpose" and "buffer" to png_ptr->chunkdata to avoid memory leaking.
+
+version 1.4.0beta23 [July 22, 2008]
+ Change "chunkdata = NULL" to "png_ptr->chunkdata = NULL" several places in
+ png_decompress_chunk().
+
+version 1.4.0beta24 [July 25, 2008]
+ Change all remaining "chunkdata" to "png_ptr->chunkdata" in
+ png_decompress_chunk(), and remove "chunkdata" from parameter list.
+ Put a call to png_check_chunk_name() in png_read_chunk_header().
+ Revised png_check_chunk_name() to reject a name with a lowercase 3rd byte.
+ Removed two calls to png_check_chunk_name() occuring later in the process.
+ Define PNG_NO_ERROR_NUMBERS by default in pngconf.h
+
+version 1.4.0beta25 [July 30, 2008]
+ Added a call to png_check_chunk_name() in pngpread.c
+ Reverted png_check_chunk_name() to accept a name with a lowercase 3rd byte.
+ Added png_push_have_buffer() function to pngpread.c
+ Eliminated PNG_BIG_ENDIAN_SUPPORTED and associated png_get_* macros.
+ Made inline expansion of png_get_*() optional with PNG_USE_READ_MACROS.
+ Eliminated all PNG_USELESS_TESTS and PNG_CORRECT_PALETTE_SUPPORTED code.
+ Synced contrib directory and configure files with libpng-1.2.30beta06.
+ Eliminated no-longer-used pngdefs.h (but it's still built in the makefiles)
+ Relocated a misplaced "#endif /* PNG_NO_WRITE_FILTER */" in pngwutil.c
+
+version 1.4.0beta26 [August 4, 2008]
+ Removed png_push_have_buffer() function in pngpread.c. It increased the
+ compiled library size slightly.
+ Changed "-Wall" to "-W -Wall" in the CFLAGS in all makefiles (Cosmin Truta)
+ Declared png_ptr "volatile" in pngread.c and pngwrite.c to avoid warnings.
+ Updated contrib/visupng/cexcept.h to version 2.0.1
+ Added PNG_LITERAL_CHARACTER macros for #, [, and ].
+
+version 1.4.0beta27 [August 5, 2008]
+ Revised usage of PNG_LITERAL_SHARP in pngerror.c.
+ Moved newline character from individual png_debug messages into the
+ png_debug macros.
+ Allow user to #define their own png_debug, png_debug1, and png_debug2.
+
+version 1.4.0beta28 [August 5, 2008]
+ Revised usage of PNG_LITERAL_SHARP in pngerror.c.
+ Added PNG_STRING_NEWLINE macro
+
+version 1.4.0beta29 [August 9, 2008]
+ Revised usage of PNG_STRING_NEWLINE to work on non-ISO compilers.
+ Added PNG_STRING_COPYRIGHT macro.
+ Added non-ISO versions of png_debug macros.
+
+version 1.4.0beta30 [August 14, 2008]
+ Added premultiplied alpha feature (Volker Wiendl).
+
+version 1.4.0beta31 [August 18, 2008]
+ Moved png_set_premultiply_alpha from pngtrans.c to pngrtran.c
+ Removed extra crc check at the end of png_handle_cHRM(). Bug introduced
+ in libpng-1.4.0beta20.
+
+version 1.4.0beta32 [August 19, 2008]
+ Added PNG_WRITE_FLUSH_SUPPORTED block around new png_flush() call.
+ Revised PNG_NO_STDIO version of png_write_flush()
+
+version 1.4.0beta33 [August 20, 2008]
+ Added png_get|set_chunk_cache_max() to limit the total number of sPLT,
+ text, and unknown chunks that can be stored.
+
+version 1.4.0beta34 [September 6, 2008]
+ Shortened tIME_string to 29 bytes in pngtest.c
+ Fixed off-by-one error introduced in png_push_read_zTXt() function in
+ libpng-1.2.30beta04/pngpread.c (Harald van Dijk)
+
+version 1.4.0beta35 [October 6, 2008]
+ Changed "trans_values" to "trans_color".
+ Changed so-number from 0 to 14. Some OS do not like 0.
+ Revised makefile.darwin to fix shared library numbering.
+ Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
+ in example.c (debian bug report)
+
+version 1.4.0beta36 [October 25, 2008]
+ Sync with tEXt vulnerability fix in libpng-1.2.33rc02.
+
+version 1.4.0beta37 [November 13, 2008]
+ Added png_check_cHRM in png.c and moved checking from pngget.c, pngrutil.c,
+ and pngwrite.c
+
+version 1.4.0beta38 [November 22, 2008]
+ Added check for zero-area RGB cHRM triangle in png_check_cHRM() and
+ png_check_cHRM_fixed().
+
+version 1.4.0beta39 [November 23, 2008]
+ Revised png_warning() to write its message on standard output by default
+ when warning_fn is NULL.
+
+version 1.4.0beta40 [November 24, 2008]
+ Eliminated png_check_cHRM(). Instead, always use png_check_cHRM_fixed().
+ In png_check_cHRM_fixed(), ensure white_y is > 0, and removed redundant
+ check for all-zero coordinates that is detected by the triangle check.
+
+version 1.4.0beta41 [November 26, 2008]
+ Fixed string vs pointer-to-string error in png_check_keyword().
+ Rearranged test expressions in png_check_cHRM_fixed() to avoid internal
+ overflows.
+ Added PNG_NO_CHECK_cHRM conditional.
+
+version 1.4.0beta42, 43 [December 1, 2008]
+ Merge png_debug with version 1.2.34beta04.
+
+version 1.4.0beta44 [December 6, 2008]
+ Removed redundant check for key==NULL before calling png_check_keyword()
+ to ensure that new_key gets initialized and removed extra warning
+ (Merge with version 1.2.34beta05 -- Arvan Pritchard).
+
+version 1.4.0beta45 [December 9, 2008]
+ In png_write_png(), respect the placement of the filler bytes in an earlier
+ call to png_set_filler() (Jim Barry).
+
+version 1.4.0beta46 [December 10, 2008]
+ Undid previous change and added PNG_TRANSFORM_STRIP_FILLER_BEFORE and
+ PNG_TRANSFORM_STRIP_FILLER_AFTER conditionals and deprecated
+ PNG_TRANSFORM_STRIP_FILLER (Jim Barry).
+
+version 1.4.0beta47 [December 15, 2008]
+ Support for dithering was disabled by default, because it has never
+ been well tested and doesn't work very well. The code has not
+ been removed, however, and can be enabled by building libpng with
+ PNG_READ_DITHER_SUPPORTED defined.
+
+version 1.4.0beta48 [February 14, 2009]
+ Added new exported function png_calloc().
+ Combined several instances of png_malloc(); png_memset() into png_calloc().
+ Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
+ but was never defined.
+
+version 1.4.0beta49 [February 28, 2009]
+ Added png_fileno() macro to pngconf.h, used in pngwio.c
+ Corrected order of #ifdef's in png_debug definition in png.h
+ Fixed bug introduced in libpng-1.4.0beta48 with the memset arguments
+ for pcal_params.
+ Fixed order of #ifdef directives in the png_debug defines in png.h
+ (bug introduced in libpng-1.2.34/1.4.0beta29).
+ Revised comments in png_set_read_fn() and png_set_write_fn().
+
+version 1.4.0beta50 [March 18, 2009]
+ Use png_calloc() instead of png_malloc() to allocate big_row_buf when
+ reading an interlaced file, to avoid a possible UMR.
+ Undid revision of PNG_NO_STDIO version of png_write_flush(). Users
+ having trouble with fflush() can build with PNG_NO_WRITE_FLUSH defined
+ or supply their own flush_fn() replacement.
+ Revised libpng*.txt and png.h documentation about use of png_write_flush()
+ and png_set_write_fn().
+ Removed fflush() from pngtest.c.
+ Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
+
+version 1.4.0beta51 [March 21, 2009]
+ Removed new png_fileno() macro from pngconf.h .
+
+version 1.4.0beta52 [March 27, 2009]
+ Relocated png_do_chop() ahead of building gamma tables in pngrtran.c
+ This avoids building 16-bit gamma tables unnecessarily.
+ Removed fflush() from pngtest.c.
+ Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
+ Added a section on differences between 1.0.x and 1.2.x to libpng.3/libpng.txt
+
+version 1.4.0beta53 [April 1, 2009]
+ Removed some remaining MMX macros from pngpriv.h
+ Fixed potential memory leak of "new_name" in png_write_iCCP() (Ralph Giles)
+
+version 1.4.0beta54 [April 13, 2009]
+ Added "ifndef PNG_SKIP_SETJMP_CHECK" block in pngconf.h to allow
+ application code writers to bypass the check for multiple inclusion
+ of setjmp.h when they know that it is safe to ignore the situation.
+ Eliminated internal use of setjmp() in pngread.c and pngwrite.c
+ Reordered ancillary chunks in pngtest.png to be the same as what
+ pngtest now produces, and made some cosmetic changes to pngtest output.
+ Eliminated deprecated png_read_init_3() and png_write_init_3() functions.
+
+version 1.4.0beta55 [April 15, 2009]
+ Simplified error handling in pngread.c and pngwrite.c by putting
+ the new png_read_cleanup() and png_write_cleanup() functions inline.
+
+version 1.4.0beta56 [April 25, 2009]
+ Renamed "user_chunk_data" to "my_user_chunk_data" in pngtest.c to suppress
+ "shadowed declaration" warning from gcc-4.3.3.
+ Renamed "gamma" to "png_gamma" in pngset.c to avoid "shadowed declaration"
+ warning about a global "gamma" variable in math.h on some platforms.
+
+version 1.4.0beta57 [May 2, 2009]
+ Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
+ but was never defined (again).
+ Rebuilt configure scripts with autoconf-2.63 instead of 2.62
+ Removed pngprefs.h and MMX from makefiles
+
+version 1.4.0beta58 [May 14, 2009]
+ Changed pngw32.def to pngwin.def in makefile.mingw (typo was introduced
+ in beta57).
+ Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri)
+
+version 1.4.0beta59 [May 15, 2009]
+ Reformated sources in libpng style (3-space intentation, comment format)
+ Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG)
+ Added sections about the git repository and our coding style to the
+ documentation
+ Relocated misplaced #endif in pngwrite.c, sCAL chunk handler.
+
+version 1.4.0beta60 [May 19, 2009]
+ Conditionally compile png_read_finish_row() which is not used by
+ progressive readers.
+ Added contrib/pngminim/preader to demonstrate building minimal progressive
+ decoder, based on contrib/gregbook with embedded libpng and zlib.
+
+version 1.4.0beta61 [May 20, 2009]
+ In contrib/pngminim/*, renamed "makefile.std" to "makefile", since there
+ is only one makefile in those directories, and revised the README files
+ accordingly.
+ More reformatting of comments, mostly to capitalize sentences.
+
+version 1.4.0beta62 [June 2, 2009]
+ Added "#define PNG_NO_WRITE_SWAP" to contrib/pngminim/encoder/pngusr.h
+ and "define PNG_NO_READ_SWAP" to decoder/pngusr.h and preader/pngusr.h
+ Reformatted several remaining "else statement" into two lines.
+ Added a section to the libpng documentation about using png_get_io_ptr()
+ in configure scripts to detect the presence of libpng.
+
+version 1.4.0beta63 [June 15, 2009]
+ Revised libpng*.txt and libpng.3 to mention calling png_set_IHDR()
+ multiple times and to specify the sample order in the tRNS chunk,
+ because the ISO PNG specification has a typo in the tRNS table.
+ Changed several PNG_UNKNOWN_CHUNK_SUPPORTED to
+ PNG_HANDLE_AS_UNKNOWN_SUPPORTED, to make the png_set_keep mechanism
+ available for ignoring known chunks even when not saving unknown chunks.
+ Adopted preference for consistent use of "#ifdef" and "#ifndef" versus
+ "#if defined()" and "if !defined()" where possible.
+
+version 1.4.0beta64 [June 24, 2009]
+ Eliminated PNG_LEGACY_SUPPORTED code.
+ Moved the various unknown chunk macro definitions outside of the
+ PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks.
+
+version 1.4.0beta65 [June 26, 2009]
+ Added a reference to the libpng license in each file.
+
+version 1.4.0beta66 [June 27, 2009]
+ Refer to the libpng license instead of the libpng license in each file.
+
+version 1.4.0beta67 [July 6, 2009]
+ Relocated INVERT_ALPHA within png_read_png() and png_write_png().
+ Added high-level API transform PNG_TRANSFORM_GRAY_TO_RGB.
+ Added an "xcode" project to the projects directory (Alam Arias).
+
+version 1.4.0beta68 [July 19, 2009]
+ Avoid some tests in filter selection in pngwutil.c
+
+version 1.4.0beta69 [July 25, 2009]
+ Simplified the new filter-selection test. This runs faster in the
+ common "PNG_ALL_FILTERS" and PNG_FILTER_NONE cases.
+ Removed extraneous declaration from the new call to png_read_gray_to_rgb()
+ (bug introduced in libpng-1.4.0beta67).
+ Fixed up xcode project (Alam Arias)
+ Added a prototype for png_64bit_product() in png.c
+
+version 1.4.0beta70 [July 27, 2009]
+ Avoid a possible NULL dereference in debug build, in png_set_text_2().
+ (bug introduced in libpng-0.95, discovered by Evan Rouault)
+
+version 1.4.0beta71 [July 29, 2009]
+ Rebuilt configure scripts with autoconf-2.64.
+
+version 1.4.0beta72 [August 1, 2009]
+ Replaced *.tar.lzma with *.tar.xz in distribution. Get the xz codec
+ from <http://tukaani.org/xz>.
+
+version 1.4.0beta73 [August 1, 2009]
+ Reject attempt to write iCCP chunk with negative embedded profile length
+ (JD Chen)
+
+version 1.4.0beta74 [August 8, 2009]
+ Changed png_ptr and info_ptr member "trans" to "trans_alpha".
+
+version 1.4.0beta75 [August 21, 2009]
+ Removed an extra png_debug() recently added to png_write_find_filter().
+ Fixed incorrect #ifdef in pngset.c regarding unknown chunk support.
+
+version 1.4.0beta76 [August 22, 2009]
+ Moved an incorrectly located test in png_read_row() in pngread.c
+
+version 1.4.0beta77 [August 27, 2009]
+ Removed lpXYZ.tar.bz2 (with CRLF), KNOWNBUG, libpng-x.y.z-KNOWNBUG.txt,
+ and the "noconfig" files from the distribution.
+ Moved CMakeLists.txt from scripts into the main libpng directory.
+ Various bugfixes and improvements to CMakeLists.txt (Philip Lowman)
+
+version 1.4.0beta78 [August 31, 2009]
+ Converted all PNG_NO_* tests to PNG_*_SUPPORTED everywhere except pngconf.h
+ Eliminated PNG_NO_FREE_ME and PNG_FREE_ME_SUPPORTED macros.
+ Use png_malloc plus a loop instead of png_calloc() to initialize
+ row_pointers in png_read_png().
+
+version 1.4.0beta79 [September 1, 2009]
+ Eliminated PNG_GLOBAL_ARRAYS and PNG_LOCAL_ARRAYS; always use local arrays.
+ Eliminated PNG_CALLOC_SUPPORTED macro and always provide png_calloc().
+
+version 1.4.0beta80 [September 17, 2009]
+ Removed scripts/libpng.icc
+ Changed typecast of filler from png_byte to png_uint_16 in png_set_filler().
+ (Dennis Gustafsson)
+ Fixed typo introduced in beta78 in pngtest.c ("#if def " should be "#ifdef ")
+
+version 1.4.0beta81 [September 23, 2009]
+ Eliminated unused PNG_FLAG_FREE_* defines from pngpriv.h
+ Expanded TAB characters in pngrtran.c
+ Removed PNG_CONST from all "PNG_CONST PNG_CHNK" declarations to avoid
+ compiler complaints about doubly declaring things "const".
+ Changed all "#if [!]defined(X)" to "if[n]def X" where possible.
+ Eliminated unused png_ptr->row_buf_size
+
+version 1.4.0beta82 [September 25, 2009]
+ Moved redundant IHDR checking into new png_check_IHDR() in png.c
+ and report all errors found in the IHDR data.
+ Eliminated useless call to png_check_cHRM() from pngset.c
+
+version 1.4.0beta83 [September 25, 2009]
+ Revised png_check_IHDR() to eliminate bogus complaint about filter_type.
+
+version 1.4.0beta84 [September 30, 2009]
+ Fixed some inconsistent indentation in pngconf.h
+ Revised png_check_IHDR() to add a test for width variable less than 32-bit.
+
+version 1.4.0beta85 [October 1, 2009]
+ Revised png_check_IHDR() again, to check info_ptr members instead of
+ the contents of the returned parameters.
+
+version 1.4.0beta86 [October 9, 2009]
+ Updated the "xcode" project (Alam Arias).
+ Eliminated a shadowed declaration of "pp" in png_handle_sPLT().
+
+version 1.4.0rc01 [October 19, 2009]
+ Trivial cosmetic changes.
+
+version 1.4.0beta87 [October 30, 2009]
+ Moved version 1.4.0 back into beta.
+
+version 1.4.0beta88 [October 30, 2009]
+ Revised libpng*.txt section about differences between 1.2.x and 1.4.0
+ because most of the new features have now been ported back to 1.2.41
+
+version 1.4.0beta89 [November 1, 2009]
+ More bugfixes and improvements to CMakeLists.txt (Philip Lowman)
+ Removed a harmless extra png_set_invert_alpha() from pngwrite.c
+ Apply png_user_chunk_cache_max within png_decompress_chunk().
+ Merged libpng-1.2.41.txt with libpng-1.4.0.txt where appropriate.
+
+version 1.4.0beta90 [November 2, 2009]
+ Removed all remaining WIN32_WCE #ifdefs except those involving the
+ time.h "tm" structure
+
+version 1.4.0beta91 [November 3, 2009]
+ Updated scripts/pngw32.def and projects/wince/png32ce.def
+ Copied projects/wince/png32ce.def to the scripts directory.
+ Added scripts/makefile.wce
+ Patched ltmain.sh for wince support.
+ Added PNG_CONVERT_tIME_SUPPORTED macro.
+
+version 1.4.0beta92 [November 4, 2009]
+ Make inclusion of time.h in pngconf.h depend on PNG_CONVERT_tIME_SUPPORTED
+ Make #define PNG_CONVERT_tIME_SUPPORTED depend on PNG_WRITE_tIME_SUPPORTED
+ Revised libpng*.txt to describe differences from 1.2.40 to 1.4.0 (instead
+ of differences from 1.2.41 to 1.4.0)
+
+version 1.4.0beta93 [November 7, 2009]
+ Added PNG_DEPSTRUCT, PNG_DEPRECATED, PNG_USE_RESULT, PNG_NORETURN, and
+ PNG_ALLOCATED macros to detect deprecated direct access to the
+ png_struct or info_struct members and other deprecated usage in
+ applications (John Bowler).
+ Updated scripts/makefile* to add "-DPNG_CONFIGURE_LIBPNG" to CFLAGS,
+ to prevent warnings about direct access to png structs by libpng
+ functions while building libpng. They need to be tested, especially
+ those using compilers other than gcc.
+ Updated projects/visualc6 and visualc71 with "/d PNG_CONFIGURE_LIBPNG".
+ They should work but still need to be updated to remove
+ references to pnggccrd.c or pngvcrd.c and ASM building.
+ Added README.txt to the beos, cbuilder5, netware, and xcode projects warning
+ that they need to be updated, to remove references to pnggccrd.c and
+ pngvcrd.c and to depend on pngpriv.h
+ Removed three direct references to read_info_ptr members in pngtest.c
+ that were detected by the new PNG_DEPSTRUCT macro.
+ Moved the png_debug macro definitions and the png_read_destroy(),
+ png_write_destroy() and png_far_to_near() prototypes from png.h
+ to pngpriv.h (John Bowler)
+ Moved the synopsis lines for png_read_destroy(), png_write_destroy()
+ png_debug(), png_debug1(), and png_debug2() from libpng.3 to libpngpf.3.
+
+version 1.4.0beta94 [November 9, 2009]
+ Removed the obsolete, unused pnggccrd.c and pngvcrd.c files.
+ Updated CMakeLists.txt to add "-DPNG_CONFIGURE_LIBPNG" to the definitions.
+ Removed dependency of pngtest.o on pngpriv.h in the makefiles.
+ Only #define PNG_DEPSTRUCT, etc. in pngconf.h if not already defined.
+
+version 1.4.0beta95 [November 10, 2009]
+ Changed png_check_sig() to !png_sig_cmp() in contrib programs.
+ Added -DPNG_CONFIGURE_LIBPNG to contrib/pngminm/*/makefile
+ Changed png_check_sig() to !png_sig_cmp() in contrib programs.
+ Corrected the png_get_IHDR() call in contrib/gregbook/readpng2.c
+ Changed pngminim/*/gather.sh to stop trying to remove pnggccrd.c and pngvcrd.c
+ Added dependency on pngpriv.h in contrib/pngminim/*/makefile
+
+version 1.4.0beta96 [November 12, 2009]
+ Renamed scripts/makefile.wce to scripts/makefile.cegcc
+ Revised Makefile.am to use libpng.sys while building libpng.so
+ so that only PNG_EXPORT functions are exported.
+ Removed the deprecated png_check_sig() function/macro.
+ Removed recently removed function names from scripts/*.def
+ Revised pngtest.png to put chunks in the same order written by pngtest
+ (evidently the same change made in libpng-1.0beta54 was lost).
+ Added PNG_PRIVATE macro definition in pngconf.h for possible future use.
+
+version 1.4.0beta97 [November 13, 2009]
+ Restored pngtest.png to the libpng-1.4.0beta7 version.
+ Removed projects/beos and netware.txt; no one seems to be supporting them.
+ Revised Makefile.in
+
+version 1.4.0beta98 [November 13, 2009]
+ Added the "xcode" project to zip distributions,
+ Fixed a typo in scripts/pngwin.def introduced in beta97.
+
+version 1.4.0beta99 [November 14, 2009]
+ Moved libpng-config.in and libpng.pc-configure.in out of the scripts
+ directory, to libpng-config.in and libpng-pc.in, respectively, and
+ modified Makefile.am and configure.ac accordingly. Now "configure"
+ needs nothing from the "scripts" directory.
+ Avoid redefining PNG_CONST in pngconf.h
+
+version 1.4.0beta100 [November 14, 2009]
+ Removed ASM builds from projects/visualc6 and projects/visualc71
+ Removed scripts/makefile.nommx and makefile.vcawin32
+ Revised CMakeLists.txt to account for new location of libpng-config.in
+ and libpng-pc.in
+ Updated INSTALL to reflect removal and relocation of files.
+
+version 1.4.0beta101 [November 14, 2009]
+ Restored the binary files (*.jpg, *.png, some project files) that were
+ accidentally deleted from the zip and 7z distributions when the xcode
+ project was added.
+
+version 1.4.0beta102 [November 18, 2009]
+ Added libpng-config.in and libpng-pc.in to the zip and 7z distributions.
+ Fixed a typo in projects/visualc6/pngtest.dsp, introduced in beta100.
+ Moved descriptions of makefiles and other scripts out of INSTALL into
+ scripts/README.txt
+ Updated the copyright year in scripts/pngwin.rc from 2006 to 2009.
+
+version 1.4.0beta103 [November 21, 2009]
+ Removed obsolete comments about ASM from projects/visualc71/README_zlib.txt
+ Align row_buf on 16-byte boundary in memory.
+ Restored the PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED guard around the call
+ to png_flush() after png_write_IEND(). See 1.4.0beta32, 1.4.0beta50
+ changes above and 1.2.30, 1.2.30rc01 and rc03 in 1.2.41 CHANGES. Someone
+ needs this feature.
+ Make the 'png_jmpbuf' macro expand to a call that records the correct
+ longjmp function as well as returning a pointer to the setjmp
+ jmp_buf buffer, and marked direct access to jmpbuf 'deprecated'.
+ (John Bowler)
+
+version 1.4.0beta104 [November 22, 2009]
+ Removed png_longjmp_ptr from scripts/*.def and libpng.3
+ Rebuilt configure scripts with autoconf-2.65
+
+version 1.4.0beta105 [November 25, 2009]
+ Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535()
+ to accomplish alpha premultiplication when
+ PNG_READ_COMPOSITE_NODIV_SUPPORTED is defined.
+ Changed "/255" to "/255.0" in background calculations to make it clear
+ that the 255 is used as a double.
+
+version 1.4.0beta106 [November 27, 2009]
+ Removed premultiplied alpha feature.
+
+version 1.4.0beta107 [December 4, 2009]
+ Updated README
+ Added "#define PNG_NO_PEDANTIC_WARNINGS" in the libpng source files.
+ Removed "-DPNG_CONFIGURE_LIBPNG" from the makefiles and projects.
+ Revised scripts/makefile.netbsd, makefile.openbsd, and makefile.sco
+ to put png.h and pngconf.h in $prefix/include, like the other scripts,
+ instead of in $prefix/include/libpng. Also revised makefile.sco
+ to put them in $prefix/include/libpng14 instead of in
+ $prefix/include/libpng/libpng14.
+
+version 1.4.0beta108 [December 11, 2009]
+ Removed leftover "-DPNG_CONFIGURE_LIBPNG" from contrib/pngminim/*/makefile
+ Relocated png_do_chop() to its original position in pngrtran.c; the
+ change in version 1.2.41beta08 caused transparency to be handled wrong
+ in some 16-bit datastreams (Yusaku Sugai).
+
+version 1.4.0beta109 [December 13, 2009]
+ Added "bit_depth" parameter to the private png_build_gamma_table() function.
+ Pass bit_depth=8 to png_build_gamma_table() when bit_depth is 16 but the
+ PNG_16_TO_8 transform has been set, to avoid unnecessary build of 16-bit
+ tables.
+
+version 1.4.0rc02 [December 20, 2009]
+ Declared png_cleanup_needed "volatile" in pngread.c and pngwrite.c
+
+version 1.4.0rc03 [December 22, 2009]
+ Renamed libpng-pc.in back to libpng.pc.in and revised CMakeLists.txt
+ (revising the change in 1.4.0beta99)
+
+version 1.4.0rc04 [December 25, 2009]
+ Swapped PNG_UNKNOWN_CHUNKS_SUPPORTED and PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ in pngset.c to be consistent with other changes in version 1.2.38.
+
+version 1.4.0rc05 [December 25, 2009]
+ Changed "libpng-pc.in" to "libpng.pc.in" in configure.ac, configure, and
+ Makefile.in to be consistent with changes in libpng-1.4.0rc03
+
+version 1.4.0rc06 [December 29, 2009]
+ Reverted the gamma_table changes from libpng-1.4.0beta109.
+ Fixed some indentation errors.
+
+version 1.4.0rc07 [January 1, 2010]
+ Revised libpng*.txt and libpng.3 about 1.2.x->1.4.x differences.
+ Use png_calloc() instead of png_malloc(); png_memset() in pngrutil.c
+ Update copyright year to 2010.
+
+version 1.4.0rc08 [January 2, 2010]
+ Avoid deprecated references to png_ptr-io_ptr and png_ptr->error_ptr
+ in pngtest.c
+
+version 1.4.0 [January 3, 2010]
+ No changes.
+
+version 1.4.1beta01 [January 8, 2010]
+ Updated CMakeLists.txt for consistent indentation and to avoid an
+ unclosed if-statement warning (Philip Lowman).
+ Revised Makefile.am and Makefile.in to remove references to Y2KINFO,
+ KNOWNBUG, and libpng.la (Robert Schwebel).
+ Revised the makefiles to install the same files and symbolic
+ links as configure, except for libpng.la and libpng14.la.
+ Make png_set|get_compression_buffer_size() available even when
+ PNG_WRITE_SUPPORTED is not enabled.
+ Revised Makefile.am and Makefile.in to simplify their maintenance.
+ Revised scripts/makefile.linux to install a link to libpng14.so.14.1
+
+version 1.4.1beta02 [January 9, 2010]
+ Revised the rest of the makefiles to install a link to libpng14.so.14.1
+
+version 1.4.1beta03 [January 10, 2010]
+ Removed png_set_premultiply_alpha() from scripts/*.def
+
+version 1.4.1rc01 [January 16, 2010]
+ No changes.
+
+version 1.4.1beta04 [January 23, 2010]
+ Revised png_decompress_chunk() to improve speed and memory usage when
+ decoding large chunks.
+ Added png_set|get_chunk_malloc_max() functions.
+
+version 1.4.1beta05 [January 26, 2010]
+ Relocated "int k" declaration in pngtest.c to minimize its scope.
+
+version 1.4.1beta06 [January 28, 2010]
+ Revised png_decompress_chunk() to use a two-pass method suggested by
+ John Bowler.
+
+version 1.4.1beta07 [February 6, 2010]
+ Folded some long lines in the source files.
+ Added defineable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX,
+ and a PNG_USER_LIMITS_SUPPORTED flag.
+ Eliminated use of png_ptr->irowbytes and reused the slot in png_ptr as
+ png_ptr->png_user_chunk_malloc_max.
+ Revised png_push_save_buffer() to do fewer but larger png_malloc() calls.
+
+version 1.4.1beta08 [February 6, 2010]
+ Minor cleanup and updating of dates and copyright year.
+
+version 1.4.1beta09 [February 7, 2010]
+ Reverted to original png_push_save_buffer() code.
+
+version 1.4.1beta10 [February 9, 2010]
+ Return allocated "old_buffer" in png_push_save_buffer() before calling
+ png_error(), to avoid a potential memory leak.
+
+version 1.4.1beta11 [February 12, 2010]
+ Relocated misplaced closing curley bracket in png_decompress_chunk().
+ Removed unused "buffer_size" variable from png_decompress_chunk().
+ Removed the cbuilder5 project, which has not been updated to 1.4.0.
+ Complete rewrite of two-pass png_decompress_chunk() by John Bowler.
+
+version 1.4.1beta12 [February 14, 2010]
+ Fixed type declaration of png_get_user_malloc_max() in pngget.c (Daisuke
+ Nishikawa)
+
+version 1.4.1rc02 [January 18, 2010]
+ No changes.
+
+version 1.4.1rc03 [February 19, 2010]
+ Noted in scripts/makefile.mingw that it expects to be run under MSYS.
+ Removed obsolete unused MMX-querying support from contrib/gregbook
+ Removed the AIX redefinition of jmpbuf in png.h
+ Define _ALL_SOURCE in configure.ac, makefile.aix, and CMakeLists.txt
+ when using AIX compiler.
+
+version 1.4.1rc04 [February 19, 2010]
+ Removed unused gzio.c from contrib/pngminim gather and makefile scripts
+
+version 1.4.1 [February 25, 2010]
+
+version 1.4.2beta01 [April 1, 2010]
+ Conditionally compile an "else" statement in png_decompress_chunk().
+ Restored the macro definition of png_check_sig().
+
+version 1.4.2rc01 [April 10, 2010]
+ No changes.
+
+version 1.4.2rc02 [April 16, 2010]
+ Documented the fact that png_set_dither() was disabled since libpng-1.4.0.
+ Reenabled png_set_dither() but renamed it to png_set_quantize() to reflect
+ more accurately what it actually does. At the same time, renamed
+ the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros to
+ PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS.
+
+version 1.4.2rc03 [April 24, 2010]
+ Added some "(long)" typecasts to printf calls in png_handle_cHRM().
+ Relaxed the overly-restrictive permissions of some files.
+
+version 1.4.2rc04 [April 28, 2010]
+ Added the "vstudio" project to replace "visualc6" and "visualc71" which
+ will be removed from libpng-1.5.0.
+ Demonstrate in example.c that lang_key should be initialized.
+ Set PNG_NO_READ_BGR, PNG_NO_IO_STATE, and PNG_NO_TIME_RFC1123 in
+ contrib/pngminim/decoder/pngusr.h to make a smaller decoder application.
+
+version 1.4.2rc05 [April 29, 2010]
+ Include png_reset_zstream() in png.c only when PNG_READ_SUPPORTED is defined.
+ Removed dummy_inflate.c and uncompr.c from contrib/pngminim/encoder
+ Corrected PNG_UNKNOWN_CHUNKS_SUPPORTED to PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ in gregbook/readpng2.c
+ Corrected protection of png_get_user_transform_ptr. The API declaration in
+ png.h is removed if both READ and WRITE USER_TRANSFORM are turned off
+ but was left defined in pngtrans.c
+
+version 1.4.2rc06 [May 3, 2010]
+ Moved declarations of umsg[] inside the proper #ifdef blocks in pngrutil.c
+
+version 1.4.2 [May 6, 2010]
+
+version 1.4.3beta01 [June 18, 2010]
+ Added missing quotation marks in the aix block of configure.ac
+ The new "vstudio" project was missing from the zip and 7z distributions.
+ In pngpread.c: png_push_have_row() add check for new_row > height
+
+version 1.4.3beta02 [June 18, 2010]
+ Removed the now-redundant check for out-of-bounds new_row from example.c
+
+version 1.4.3beta03 [June 18, 2010]
+ In pngpread.c: png_push_finish_row() add check for too many rows.
+
+version 1.4.3beta04 [June 19, 2010]
+ In pngpread.c: png_push_process_row() add check for too many rows.
+ Removed the checks added in beta01 and beta03, as they are now redundant.
+
+version 1.4.3beta05 [June 20, 2010]
+ Rewrote png_process_IDAT_data to consistently treat extra data as warnings
+ and handle end conditions more cleanly.
+ Removed the new (beta04) check in png_push_process_row().
+
+version 1.4.3rc01 [June 21, 2010]
+ Revised some comments in png_process_IDAT_data().
+
+version 1.4.3rc02 [June 22, 2010]
+ Changed char *msg to PNG_CONST char *msg in pngrutil.c
+ Stop memory leak when reading a malformed sCAL chunk.
+ Removed some trailing blanks.
+
+version 1.4.3rc03 [June 23, 2010]
+ Revised pngpread.c patch of beta05 to avoid an endless loop.
+
+version 1.4.3 [June 26, 2010]
+ Updated some of the "last changed" dates.
+
+version 1.4.4beta01 [July 12, 2010]
+ Removed extraneous new_push_process_row.c file.
+ Revised the "SEE ALSO" style of libpng.3, libpngpf.3, and png.5
+ Removed some newly-added TAB characters from pngpread.c.
+ Fixed some indentation in pngpread.c and pngrutil.c
+ Changed "extern PNG_EXPORT" to "PNG_EXPORT" in png.h (Jan Nijtmans)
+ Changed "extern" to "PNG_EXTERN" in pngpriv.h (except for the 'extern "C" {')
+ Put "#ifndef PNG_EXTERN, #endif" around "#define PNG_EXTERN" in pngpriv.h
+
+version 1.4.4beta02 [July 24, 2010]
+ Added -DNO_PNG_SNPRINTF to CFLAGS in scripts/makefile.dj2
+ Moved the definition of png_snprintf() outside of the enclosing
+ #ifdef blocks in pngconf.h
+ Added a special case typedef of png_longjmp_ptr for WATCOM.
+
+version 1.4.4beta03 [July 24, 2010]
+ Removed reference to cbuilder5/* from Makefile.in and Makefile.am
+ Eliminated the new special case typedef of png_longjmp_ptr for WATCOM
+ and made a special case "#define PNGAPI" in pngconf.h instead.
+
+version 1.4.4beta04 [July 31, 2010]
+ Updated the read macros and functions from 1.5.0beta38.
+
+version 1.4.4beta05 [August 6, 2010]
+ Updated projects/visualc71 so it can find scripts/pnglibconf.h
+ Removed unused png_mem_* defines from pngconf.h.
+ Correct use of _WINDOWS_ in pngconf.h
+
+version 1.4.4beta06 [August 11, 2010]
+ Don't try to use version-script with cygwin/mingw.
+ Revised contrib/gregbook to work under cygwin/mingw.
+
+version 1.4.4beta07 [August 26, 2010]
+ Updated prebuilt aclocal.m4 and ltmain.sh
+ Add .dll.a to the list of extensions to be symlinked by Makefile.am (Yaakov)
+ Updated CMakeLists.txt to use CMAKE_INSTALL_LIBDIR variable; useful for
+ installing libpng in /usr/lib64 (Funda Wang).
+ Revised CMakeLists.txt to put the man pages in share/man/man* not man/man*
+ Revised CMakeLists.txt to make symlinks instead of copies when installing.
+ Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman)
+ Moved "#include pngusr.h" ahead of PNG_USER_PRIVATEBUILD test in pngconf.h
+ Eliminated a deprecated reference to png_ptr->io_ptr in pngtest.c
+ Eliminated new unnecessary #if tests regarding the sCAL chunk from pngrutil.c
+
+version 1.4.4beta08 [September 2, 2010]
+ Updated the xcode project to work with libpng-1.4.x and added iOS targets
+ for simulator and device (Philippe Hausler).
+
+version 1.4.4rc01 [September 10, 2010]
+ No changes.
+
+version 1.4.4rc02 [September 13, 2010]
+ Revised CMakeLists.txt (Philip Lowman).
+
+version 1.4.4rc03 [September 14, 2010]
+ Removed an extraneous close-double-quote from CMakeLists.txt
+ Eliminated another deprecated reference to png_ptr->io_ptr in pngtest.c
+
+version 1.4.4rc04 [September 16, 2010]
+ Fixed indentation and removed debugging message from CMakeLists.txt
+ Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER,
+ $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
+
+version 1.4.4rc05 [September 20, 2010]
+ Rebuilt configure scripts with automake-1.11.1 instead of automake-1.11.
+ Removed unused mkinstalldirs file.
+
+version 1.4.4 [September 23, 2010]
+ No changes.
+
+Send comments/corrections/commendations to glennrp at users.sourceforge.net
+or to png-mng-implement at lists.sf.net (subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement).
+
+Glenn R-P
+*/ }
+#endif
--- /dev/null
+
+This copy of the libpng notices is provided for your convenience. In case of
+any discrepancy between this copy and the notices in the file png.h that is
+included in the libpng distribution, the latter shall prevail.
+
+COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+
+If you modify libpng you may insert additional notices immediately following
+this sentence.
+
+This code is released under the libpng license.
+
+libpng versions 1.2.6, August 15, 2004, through 1.4.4, September 23, 2010, are
+Copyright (c) 2004, 2006-2010 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-1.2.5
+with the following individual added to the list of Contributing Authors
+
+ Cosmin Truta
+
+libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are
+Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-1.0.6
+with the following individuals added to the list of Contributing Authors
+
+ Simon-Pierre Cadieux
+ Eric S. Raymond
+ Gilles Vollant
+
+and with the following additions to the disclaimer:
+
+ There is no warranty against interference with your enjoyment of the
+ library or against infringement. There is no warranty that our
+ efforts or the library will fulfill any of your particular purposes
+ or needs. This library is provided with all faults, and the entire
+ risk of satisfactory quality, performance, accuracy, and effort is with
+ the user.
+
+libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+Copyright (c) 1998, 1999 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-0.96,
+with the following individuals added to the list of Contributing Authors:
+
+ Tom Lane
+ Glenn Randers-Pehrson
+ Willem van Schaik
+
+libpng versions 0.89, June 1996, through 0.96, May 1997, are
+Copyright (c) 1996, 1997 Andreas Dilger
+Distributed according to the same disclaimer and license as libpng-0.88,
+with the following individuals added to the list of Contributing Authors:
+
+ John Bowler
+ Kevin Bracey
+ Sam Bushell
+ Magnus Holmgren
+ Greg Roelofs
+ Tom Tanner
+
+libpng versions 0.5, May 1995, through 0.88, January 1996, are
+Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+
+For the purposes of this copyright and license, "Contributing Authors"
+is defined as the following set of individuals:
+
+ Andreas Dilger
+ Dave Martindale
+ Guy Eric Schalnat
+ Paul Schmidt
+ Tim Wegner
+
+The PNG Reference Library is supplied "AS IS". The Contributing Authors
+and Group 42, Inc. disclaim all warranties, expressed or implied,
+including, without limitation, the warranties of merchantability and of
+fitness for any purpose. The Contributing Authors and Group 42, Inc.
+assume no liability for direct, indirect, incidental, special, exemplary,
+or consequential damages, which may result from the use of the PNG
+Reference Library, even if advised of the possibility of such damage.
+
+Permission is hereby granted to use, copy, modify, and distribute this
+source code, or portions hereof, for any purpose, without fee, subject
+to the following restrictions:
+
+1. The origin of this source code must not be misrepresented.
+
+2. Altered versions must be plainly marked as such and must not
+ be misrepresented as being the original source.
+
+3. This Copyright notice may not be removed or altered from any
+ source or altered source distribution.
+
+The Contributing Authors and Group 42, Inc. specifically permit, without
+fee, and encourage the use of this source code as a component to
+supporting the PNG file format in commercial products. If you use this
+source code in a product, acknowledgment is not required but would be
+appreciated.
+
+
+A "png_get_copyright" function is available, for convenient use in "about"
+boxes and the like:
+
+ printf("%s",png_get_copyright(NULL));
+
+Also, the PNG logo (in PNG format, of course) is supplied in the
+files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+
+Libpng is OSI Certified Open Source Software. OSI Certified Open Source is a
+certification mark of the Open Source Initiative.
+
+Glenn Randers-Pehrson
+glennrp at users.sourceforge.net
+September 23, 2010
--- /dev/null
+README for libpng version 1.4.4 - September 23, 2010 (shared library 14.0)
+See the note about version numbers near the top of png.h
+
+See INSTALL for instructions on how to install libpng.
+
+Libpng comes in several distribution formats. Get libpng-*.tar.gz,
+libpng-*.tar.xz or libpng-*.tar.bz2 if you want UNIX-style line endings
+in the text files, or lpng*.zip if you want DOS-style line endings.
+
+Version 0.89 was the first official release of libpng. Don't let the
+fact that it's the first release fool you. The libpng library has been in
+extensive use and testing since mid-1995. By late 1997 it had
+finally gotten to the stage where there hadn't been significant
+changes to the API in some time, and people have a bad feeling about
+libraries with versions < 1.0. Version 1.0.0 was released in
+March 1998.
+
+****
+Note that some of the changes to the png_info structure render this
+version of the library binary incompatible with libpng-0.89 or
+earlier versions if you are using a shared library. The type of the
+"filler" parameter for png_set_filler() has changed from png_byte to
+png_uint_32, which will affect shared-library applications that use
+this function.
+
+To avoid problems with changes to the internals of png_info_struct,
+new APIs have been made available in 0.95 to avoid direct application
+access to info_ptr. These functions are the png_set_<chunk> and
+png_get_<chunk> functions. These functions should be used when
+accessing/storing the info_struct data, rather than manipulating it
+directly, to avoid such problems in the future.
+
+It is important to note that the APIs do not make current programs
+that access the info struct directly incompatible with the new
+library. However, it is strongly suggested that new programs use
+the new APIs (as shown in example.c and pngtest.c), and older programs
+be converted to the new format, to facilitate upgrades in the future.
+****
+
+Additions since 0.90 include the ability to compile libpng as a
+Windows DLL, and new APIs for accessing data in the info struct.
+Experimental functions include the ability to set weighting and cost
+factors for row filter selection, direct reads of integers from buffers
+on big-endian processors that support misaligned data access, faster
+methods of doing alpha composition, and more accurate 16->8 bit color
+conversion.
+
+The additions since 0.89 include the ability to read from a PNG stream
+which has had some (or all) of the signature bytes read by the calling
+application. This also allows the reading of embedded PNG streams that
+do not have the PNG file signature. As well, it is now possible to set
+the library action on the detection of chunk CRC errors. It is possible
+to set different actions based on whether the CRC error occurred in a
+critical or an ancillary chunk.
+
+The changes made to the library, and bugs fixed are based on discussions
+on the PNG-implement mailing list and not on material submitted
+privately to Guy, Andreas, or Glenn. They will forward any good
+suggestions to the list.
+
+For a detailed description on using libpng, read libpng.txt. For
+examples of libpng in a program, see example.c and pngtest.c. For usage
+information and restrictions (what little they are) on libpng, see
+png.h. For a description on using zlib (the compression library used by
+libpng) and zlib's restrictions, see zlib.h
+
+I have included a general makefile, as well as several machine and
+compiler specific ones, but you may have to modify one for your own needs.
+
+You should use zlib 1.0.4 or later to run this, but it MAY work with
+versions as old as zlib 0.95. Even so, there are bugs in older zlib
+versions which can cause the output of invalid compression streams for
+some images. You will definitely need zlib 1.0.4 or later if you are
+taking advantage of the MS-DOS "far" structure allocation for the small
+and medium memory models. You should also note that zlib is a
+compression library that is useful for more things than just PNG files.
+You can use zlib as a drop-in replacement for fread() and fwrite() if
+you are so inclined.
+
+zlib should be available at the same place that libpng is, or at.
+ftp://ftp.info-zip.org/pub/infozip/zlib
+
+You may also want a copy of the PNG specification. It is available
+as an RFC, a W3C Recommendation, and an ISO/IEC Standard. You can find
+these at http://www.libpng.org/pub/png/documents/
+
+This code is currently being archived at libpng.sf.net in the
+[DOWNLOAD] area, and on CompuServe, Lib 20 (PNG SUPPORT)
+at GO GRAPHSUP. If you can't find it in any of those places,
+e-mail me, and I'll help you find it.
+
+If you have any code changes, requests, problems, etc., please e-mail
+them to me. Also, I'd appreciate any make files or project files,
+and any modifications you needed to make to get libpng to compile,
+along with a #define variable to tell what compiler/system you are on.
+If you needed to add transformations to libpng, or wish libpng would
+provide the image in a different way, drop me a note (and code, if
+possible), so I can consider supporting the transformation.
+Finally, if you get any warning messages when compiling libpng
+(note: not zlib), and they are easy to fix, I'd appreciate the
+fix. Please mention "libpng" somewhere in the subject line. Thanks.
+
+This release was created and will be supported by myself (of course
+based in a large way on Guy's and Andreas' earlier work), and the PNG
+development group.
+
+Send comments/corrections/commendations to png-mng-implement at
+lists.sourceforge.net (subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe) or to glennrp at users.sourceforge.net
+
+You can't reach Guy, the original libpng author, at the addresses
+given in previous versions of this document. He and Andreas will
+read mail addressed to the png-implement list, however.
+
+Please do not send general questions about PNG. Send them to
+the (png-list at ccrc.wustl.edu, subscription required, write to
+majordomo at ccrc.wustl.edu with "subscribe png-list" in your message).
+On the other hand,
+please do not send libpng questions to that address, send them to me
+or to the png-implement list. I'll
+get them in the end anyway. If you have a question about something
+in the PNG specification that is related to using libpng, send it
+to me. Send me any questions that start with "I was using libpng,
+and ...". If in doubt, send questions to me. I'll bounce them
+to others, if necessary.
+
+Please do not send suggestions on how to change PNG. We have
+been discussing PNG for nine years now, and it is official and
+finished. If you have suggestions for libpng, however, I'll
+gladly listen. Even if your suggestion is not used immediately,
+it may be used later.
+
+Files in this distribution:
+
+ ANNOUNCE => Announcement of this version, with recent changes
+ CHANGES => Description of changes between libpng versions
+ KNOWNBUG => List of known bugs and deficiencies
+ LICENSE => License to use and redistribute libpng
+ README => This file
+ TODO => Things not implemented in the current library
+ Y2KINFO => Statement of Y2K compliance
+ example.c => Example code for using libpng functions
+ libpng.3 => manual page for libpng (includes libpng.txt)
+ libpng.txt => Description of libpng and its functions
+ libpngpf.3 => manual page for libpng's private functions
+ png.5 => manual page for the PNG format
+ png.c => Basic interface functions common to library
+ png.h => Library function and interface declarations
+ pngconf.h => System specific library configuration
+ pngerror.c => Error/warning message I/O functions
+ pngget.c => Functions for retrieving info from struct
+ pngmem.c => Memory handling functions
+ pngbar.png => PNG logo, 88x31
+ pngnow.png => PNG logo, 98x31
+ pngpread.c => Progressive reading functions
+ pngread.c => Read data/helper high-level functions
+ pngrio.c => Lowest-level data read I/O functions
+ pngrtran.c => Read data transformation functions
+ pngrutil.c => Read data utility functions
+ pngset.c => Functions for storing data into the info_struct
+ pngtest.c => Library test program
+ pngtest.png => Library test sample image
+ pngtrans.c => Common data transformation functions
+ pngwio.c => Lowest-level write I/O functions
+ pngwrite.c => High-level write functions
+ pngwtran.c => Write data transformations
+ pngwutil.c => Write utility functions
+ contrib => Contributions
+ gregbook => source code for PNG reading and writing, from
+ Greg Roelofs' "PNG: The Definitive Guide",
+ O'Reilly, 1999
+ msvctest => Builds and runs pngtest using a MSVC workspace
+ pngminus => Simple pnm2png and png2pnm programs
+ pngsuite => Test images
+ visupng => Contains a MSVC workspace for VisualPng
+ projects => Contains project files and workspaces for
+ building a DLL
+ c5builder => Contains a Borland workspace for building
+ libpng and zlib
+ visualc6 => Contains a Microsoft Visual C++ (MSVC)
+ workspace for building libpng and zlib
+ scripts => Directory containing scripts for building libpng:
+ descrip.mms => VMS makefile for MMS or MMK
+ makefile.std => Generic UNIX makefile (cc, creates static
+ libpng.a)
+ makefile.elf => Linux/ELF makefile symbol versioning,
+ (gcc, creates libpng14.so.14.1.4.4)
+ makefile.linux => Linux/ELF makefile
+ (gcc, creates libpng14.so.14.1.4.4)
+ makefile.gcc => Generic makefile (gcc, creates static libpng.a)
+ makefile.knr => Archaic UNIX Makefile that converts files with
+ ansi2knr (Requires ansi2knr.c from
+ ftp://ftp.cs.wisc.edu/ghost)
+ makefile.aix => AIX makefile
+ makefile.cygwin => Cygwin/gcc makefile
+ makefile.darwin => Darwin makefile
+ makefile.dec => DEC Alpha UNIX makefile
+ makefile.freebsd => FreeBSD makefile
+ makefile.hpgcc => HPUX makefile using gcc
+ makefile.hpux => HPUX (10.20 and 11.00) makefile
+ makefile.hp64 => HPUX (10.20 and 11.00) makefile, 64 bit
+ makefile.ibmc => IBM C/C++ version 3.x for Win32 and OS/2 (static)
+ makefile.intel => Intel C/C++ version 4.0 and later
+ makefile.mingw => Mingw/gcc makefile
+ makefile.netbsd => NetBSD/cc makefile, makes libpng.so.
+ makefile.ne14bsd => NetBSD/cc makefile, makes
+ libpng14.so
+ makefile.openbsd => OpenBSD makefile
+ makefile.sgi => Silicon Graphics IRIX (cc, creates static lib)
+ makefile.sggcc => Silicon Graphics
+ (gcc, creates libpng14.so.14.1.4.4)
+ makefile.sunos => Sun makefile
+ makefile.solaris => Solaris 2.X makefile
+ (gcc, creates libpng14.so.14.1.4.4)
+ makefile.so9 => Solaris 9 makefile
+ (gcc, creates libpng14.so.14.1.4.4)
+ makefile.32sunu => Sun Ultra 32-bit makefile
+ makefile.64sunu => Sun Ultra 64-bit makefile
+ makefile.sco => For SCO OSr5 ELF and Unixware 7 with Native cc
+ makefile.mips => MIPS makefile
+ makefile.acorn => Acorn makefile
+ makefile.amiga => Amiga makefile
+ smakefile.ppc => AMIGA smakefile for SAS C V6.58/7.00 PPC
+ compiler (Requires SCOPTIONS, copied from
+ scripts/SCOPTIONS.ppc)
+ makefile.atari => Atari makefile
+ makefile.beos => BEOS makefile for X86
+ makefile.bor => Borland makefile (uses bcc)
+ makefile.bc32 => 32-bit Borland C++ (all modules compiled in C mode)
+ makefile.tc3 => Turbo C 3.0 makefile
+ makefile.dj2 => DJGPP 2 makefile
+ makefile.msc => Microsoft C makefile
+ makefile.vcwin32 => makefile for Microsoft Visual C++ 4.0 and
+ later (does not use assembler code)
+ makefile.os2 => OS/2 Makefile (gcc and emx, requires pngos2.def)
+ png32ce.def => module definition for makefile.cegccg
+ pngos2.def => OS/2 module definition file used by
+ makefile.os2
+ pngwin.def => module definition file used by
+ makefile.cygwin and makefile.mingw
+ makefile.watcom => Watcom 10a+ Makefile, 32-bit flat memory model
+ makevms.com => VMS build script
+ SCOPTIONS.ppc => Used with smakefile.ppc
+
+Good luck, and happy coding.
+
+-Glenn Randers-Pehrson (current maintainer, since 1998)
+ Internet: glennrp at users.sourceforge.net
+
+-Andreas Eric Dilger (former maintainer, 1996-1997)
+ Internet: adilger at enel.ucalgary.ca
+ Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/
+
+-Guy Eric Schalnat (original author and former maintainer, 1995-1996)
+ (formerly of Group 42, Inc)
+ Internet: gschal at infinet.com
--- /dev/null
+/*
+TODO - list of things to do for libpng:
+
+Final bug fixes.
+Improve API by hiding the png_struct and png_info structs.
+Finish work on the no-floating-point version (including gamma compensation)
+Better C++ wrapper/full C++ implementation?
+Fix problem with C++ and EXTERN "C".
+cHRM transformation.
+Improve setjmp/longjmp usage or remove it in favor of returning error codes.
+Add "grayscale->palette" transformation and "palette->grayscale" detection.
+Improved quantizing and dithering.
+Multi-lingual error and warning message support.
+Complete sRGB transformation (presently it simply uses gamma=0.45455).
+Man pages for function calls.
+Better documentation.
+Better filter selection
+ (counting huffman bits/precompression? filter inertia? filter costs?).
+Histogram creation.
+Text conversion between different code pages (Latin-1 -> Mac and DOS).
+Build gamma tables using fixed point (and do away with floating point entirely).
+Avoid building gamma tables whenever possible.
+Use greater precision when changing to linear gamma for compositing against
+ background and doing rgb-to-gray transformation.
+Investigate pre-incremented loop counters and other loop constructions.
+Add interpolated method of handling interlacing.
+Provide for conditional compilation of 16-bit support (except for the
+ initial stripping down to 8-bits when reading a 16-bit PNG datastream).
+Switch to the simpler zlib (zlib/libpng) license if legally possible.
+
+*/
--- /dev/null
+libpng.txt - A description on how to use and modify libpng
+
+ libpng version 1.4.4 - September 23, 2010
+ Updated and distributed by Glenn Randers-Pehrson
+ <glennrp at users.sourceforge.net>
+ Copyright (c) 1998-2010 Glenn Randers-Pehrson
+
+ This document is released under the libpng license.
+ For conditions of distribution and use, see the disclaimer
+ and license in png.h
+
+ Based on:
+
+ libpng versions 0.97, January 1998, through 1.4.4 - September 23, 2010
+ Updated and distributed by Glenn Randers-Pehrson
+ Copyright (c) 1998-2010 Glenn Randers-Pehrson
+
+ libpng 1.0 beta 6 version 0.96 May 28, 1997
+ Updated and distributed by Andreas Dilger
+ Copyright (c) 1996, 1997 Andreas Dilger
+
+ libpng 1.0 beta 2 - version 0.88 January 26, 1996
+ For conditions of distribution and use, see copyright
+ notice in png.h. Copyright (c) 1995, 1996 Guy Eric
+ Schalnat, Group 42, Inc.
+
+ Updated/rewritten per request in the libpng FAQ
+ Copyright (c) 1995, 1996 Frank J. T. Wojcik
+ December 18, 1995 & January 20, 1996
+
+I. Introduction
+
+This file describes how to use and modify the PNG reference library
+(known as libpng) for your own use. There are five sections to this
+file: introduction, structures, reading, writing, and modification and
+configuration notes for various special platforms. In addition to this
+file, example.c is a good starting point for using the library, as
+it is heavily commented and should include everything most people
+will need. We assume that libpng is already installed; see the
+INSTALL file for instructions on how to install libpng.
+
+For examples of libpng usage, see the files "example.c", "pngtest.c",
+and the files in the "contrib" directory, all of which are included in
+the libpng distribution.
+
+Libpng was written as a companion to the PNG specification, as a way
+of reducing the amount of time and effort it takes to support the PNG
+file format in application programs.
+
+The PNG specification (second edition), November 2003, is available as
+a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at
+<http://www.w3.org/TR/2003/REC-PNG-20031110/
+The W3C and ISO documents have identical technical content.
+
+The PNG-1.2 specification is available at
+<http://www.libpng.org/pub/png/documents/>. It is technically equivalent
+to the PNG specification (second edition) but has some additional material.
+
+The PNG-1.0 specification is available
+as RFC 2083 <http://www.libpng.org/pub/png/documents/> and as a
+W3C Recommendation <http://www.w3.org/TR/REC.png.html>.
+
+Some additional chunks are described in the special-purpose public chunks
+documents at <http://www.libpng.org/pub/png/documents/>.
+
+Other information
+about PNG, and the latest version of libpng, can be found at the PNG home
+page, <http://www.libpng.org/pub/png/>.
+
+Most users will not have to modify the library significantly; advanced
+users may want to modify it more. All attempts were made to make it as
+complete as possible, while keeping the code easy to understand.
+Currently, this library only supports C. Support for other languages
+is being considered.
+
+Libpng has been designed to handle multiple sessions at one time,
+to be easily modifiable, to be portable to the vast majority of
+machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy
+to use. The ultimate goal of libpng is to promote the acceptance of
+the PNG file format in whatever way possible. While there is still
+work to be done (see the TODO file), libpng should cover the
+majority of the needs of its users.
+
+Libpng uses zlib for its compression and decompression of PNG files.
+Further information about zlib, and the latest version of zlib, can
+be found at the zlib home page, <http://www.info-zip.org/pub/infozip/zlib/>.
+The zlib compression utility is a general purpose utility that is
+useful for more than PNG files, and can be used without libpng.
+See the documentation delivered with zlib for more details.
+You can usually find the source files for the zlib utility wherever you
+find the libpng source files.
+
+Libpng is thread safe, provided the threads are using different
+instances of the structures. Each thread should have its own
+png_struct and png_info instances, and thus its own image.
+Libpng does not protect itself against two threads using the
+same instance of a structure.
+
+II. Structures
+
+There are two main structures that are important to libpng, png_struct
+and png_info. The first, png_struct, is an internal structure that
+will not, for the most part, be used by a user except as the first
+variable passed to every libpng function call.
+
+The png_info structure is designed to provide information about the
+PNG file. At one time, the fields of png_info were intended to be
+directly accessible to the user. However, this tended to cause problems
+with applications using dynamically loaded libraries, and as a result
+a set of interface functions for png_info (the png_get_*() and png_set_*()
+functions) was developed. The fields of png_info are still available for
+older applications, but it is suggested that applications use the new
+interfaces if at all possible.
+
+Applications that do make direct access to the members of png_struct (except
+for png_ptr->jmpbuf) must be recompiled whenever the library is updated,
+and applications that make direct access to the members of png_info must
+be recompiled if they were compiled or loaded with libpng version 1.0.6,
+in which the members were in a different order. In version 1.0.7, the
+members of the png_info structure reverted to the old order, as they were
+in versions 0.97c through 1.0.5. Starting with version 2.0.0, both
+structures are going to be hidden, and the contents of the structures will
+only be accessible through the png_get/png_set functions.
+
+The png.h header file is an invaluable reference for programming with libpng.
+And while I'm on the topic, make sure you include the libpng header file:
+
+#include <png.h>
+
+III. Reading
+
+We'll now walk you through the possible functions to call when reading
+in a PNG file sequentially, briefly explaining the syntax and purpose
+of each one. See example.c and png.h for more detail. While
+progressive reading is covered in the next section, you will still
+need some of the functions discussed in this section to read a PNG
+file.
+
+Setup
+
+You will want to do the I/O initialization(*) before you get into libpng,
+so if it doesn't work, you don't have much to undo. Of course, you
+will also want to insure that you are, in fact, dealing with a PNG
+file. Libpng provides a simple check to see if a file is a PNG file.
+To use it, pass in the first 1 to 8 bytes of the file to the function
+png_sig_cmp(), and it will return 0 (false) if the bytes match the
+corresponding bytes of the PNG signature, or nonzero (true) otherwise.
+Of course, the more bytes you pass in, the greater the accuracy of the
+prediction.
+
+If you are intending to keep the file pointer open for use in libpng,
+you must ensure you don't read more than 8 bytes from the beginning
+of the file, and you also have to make a call to png_set_sig_bytes_read()
+with the number of bytes you read from the beginning. Libpng will
+then only check the bytes (if any) that your program didn't read.
+
+(*): If you are not using the standard I/O functions, you will need
+to replace them with custom functions. See the discussion under
+Customizing libpng.
+
+
+ FILE *fp = fopen(file_name, "rb");
+ if (!fp)
+ {
+ return (ERROR);
+ }
+ fread(header, 1, number, fp);
+ is_png = !png_sig_cmp(header, 0, number);
+ if (!is_png)
+ {
+ return (NOT_PNG);
+ }
+
+
+Next, png_struct and png_info need to be allocated and initialized. In
+order to ensure that the size of these structures is correct even with a
+dynamically linked libpng, there are functions to initialize and
+allocate the structures. We also pass the library version, optional
+pointers to error handling functions, and a pointer to a data struct for
+use by the error functions, if necessary (the pointer and functions can
+be NULL if the default error handlers are to be used). See the section
+on Changes to Libpng below regarding the old initialization functions.
+The structure allocation functions quietly return NULL if they fail to
+create the structure, so your application should check for that.
+
+ png_structp png_ptr = png_create_read_struct
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ user_error_fn, user_warning_fn);
+ if (!png_ptr)
+ return (ERROR);
+
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+ if (!info_ptr)
+ {
+ png_destroy_read_struct(&png_ptr,
+ (png_infopp)NULL, (png_infopp)NULL);
+ return (ERROR);
+ }
+
+ png_infop end_info = png_create_info_struct(png_ptr);
+ if (!end_info)
+ {
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ (png_infopp)NULL);
+ return (ERROR);
+ }
+
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_read_struct_2() instead of png_create_read_struct():
+
+ png_structp png_ptr = png_create_read_struct_2
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ user_error_fn, user_warning_fn, (png_voidp)
+ user_mem_ptr, user_malloc_fn, user_free_fn);
+
+The error handling routines passed to png_create_read_struct()
+and the memory alloc/free routines passed to png_create_struct_2()
+are only necessary if you are not using the libpng supplied error
+handling and memory alloc/free functions.
+
+When libpng encounters an error, it expects to longjmp back
+to your routine. Therefore, you will need to call setjmp and pass
+your png_jmpbuf(png_ptr). If you read the file from different
+routines, you will need to update the jmpbuf field every time you enter
+a new routine that will call a png_*() function.
+
+See your documentation of setjmp/longjmp for your compiler for more
+information on setjmp/longjmp. See the discussion on libpng error
+handling in the Customizing Libpng section below for more information
+on the libpng error handling. If an error occurs, and libpng longjmp's
+back to your setjmp, you will want to call png_destroy_read_struct() to
+free any memory.
+
+ if (setjmp(png_jmpbuf(png_ptr)))
+ {
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ &end_info);
+ fclose(fp);
+ return (ERROR);
+ }
+
+If you would rather avoid the complexity of setjmp/longjmp issues,
+you can compile libpng with PNG_NO_SETJMP, in which case
+errors will result in a call to PNG_ABORT() which defaults to abort().
+
+You can #define PNG_ABORT() to a function that does something
+more useful than abort(), as long as your function does not
+return.
+
+Now you need to set up the input code. The default for libpng is to
+use the C function fread(). If you use this, you will need to pass a
+valid FILE * in the function png_init_io(). Be sure that the file is
+opened in binary mode. If you wish to handle reading data in another
+way, you need not call the png_init_io() function, but you must then
+implement the libpng I/O methods discussed in the Customizing Libpng
+section below.
+
+ png_init_io(png_ptr, fp);
+
+If you had previously opened the file and read any of the signature from
+the beginning in order to see if this was a PNG file, you need to let
+libpng know that there are some bytes missing from the start of the file.
+
+ png_set_sig_bytes(png_ptr, number);
+
+You can change the zlib compression buffer size to be used while
+reading compressed data with
+
+ png_set_compression_buffer_size(png_ptr, buffer_size);
+
+where the default size is 8192 bytes. Note that the buffer size
+is changed immediately and the buffer is reallocated immediately,
+instead of setting a flag to be acted upon later.
+
+Setting up callback code
+
+You can set up a callback function to handle any unknown chunks in the
+input stream. You must supply the function
+
+ read_chunk_callback(png_ptr ptr,
+ png_unknown_chunkp chunk);
+ {
+ /* The unknown chunk structure contains your
+ chunk data, along with similar data for any other
+ unknown chunks: */
+
+ png_byte name[5];
+ png_byte *data;
+ png_size_t size;
+
+ /* Note that libpng has already taken care of
+ the CRC handling */
+
+ /* put your code here. Search for your chunk in the
+ unknown chunk structure, process it, and return one
+ of the following: */
+
+ return (-n); /* chunk had an error */
+ return (0); /* did not recognize */
+ return (n); /* success */
+ }
+
+(You can give your function another name that you like instead of
+"read_chunk_callback")
+
+To inform libpng about your function, use
+
+ png_set_read_user_chunk_fn(png_ptr, user_chunk_ptr,
+ read_chunk_callback);
+
+This names not only the callback function, but also a user pointer that
+you can retrieve with
+
+ png_get_user_chunk_ptr(png_ptr);
+
+If you call the png_set_read_user_chunk_fn() function, then all unknown
+chunks will be saved when read, in case your callback function will need
+one or more of them. This behavior can be changed with the
+png_set_keep_unknown_chunks() function, described below.
+
+At this point, you can set up a callback function that will be
+called after each row has been read, which you can use to control
+a progress meter or the like. It's demonstrated in pngtest.c.
+You must supply a function
+
+ void read_row_callback(png_ptr ptr, png_uint_32 row,
+ int pass);
+ {
+ /* put your code here */
+ }
+
+(You can give it another name that you like instead of "read_row_callback")
+
+To inform libpng about your function, use
+
+ png_set_read_status_fn(png_ptr, read_row_callback);
+
+Unknown-chunk handling
+
+Now you get to set the way the library processes unknown chunks in the
+input PNG stream. Both known and unknown chunks will be read. Normal
+behavior is that known chunks will be parsed into information in
+various info_ptr members while unknown chunks will be discarded. This
+behavior can be wasteful if your application will never use some known
+chunk types. To change this, you can call:
+
+ png_set_keep_unknown_chunks(png_ptr, keep,
+ chunk_list, num_chunks);
+ keep - 0: default unknown chunk handling
+ 1: ignore; do not keep
+ 2: keep only if safe-to-copy
+ 3: keep even if unsafe-to-copy
+ You can use these definitions:
+ PNG_HANDLE_CHUNK_AS_DEFAULT 0
+ PNG_HANDLE_CHUNK_NEVER 1
+ PNG_HANDLE_CHUNK_IF_SAFE 2
+ PNG_HANDLE_CHUNK_ALWAYS 3
+ chunk_list - list of chunks affected (a byte string,
+ five bytes per chunk, NULL or '\0' if
+ num_chunks is 0)
+ num_chunks - number of chunks affected; if 0, all
+ unknown chunks are affected. If nonzero,
+ only the chunks in the list are affected
+
+Unknown chunks declared in this way will be saved as raw data onto a
+list of png_unknown_chunk structures. If a chunk that is normally
+known to libpng is named in the list, it will be handled as unknown,
+according to the "keep" directive. If a chunk is named in successive
+instances of png_set_keep_unknown_chunks(), the final instance will
+take precedence. The IHDR and IEND chunks should not be named in
+chunk_list; if they are, libpng will process them normally anyway.
+
+Here is an example of the usage of png_set_keep_unknown_chunks(),
+where the private "vpAg" chunk will later be processed by a user chunk
+callback function:
+
+ png_byte vpAg[5]={118, 112, 65, 103, (png_byte) '\0'};
+
+ #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+ png_byte unused_chunks[]=
+ {
+ 104, 73, 83, 84, (png_byte) '\0', /* hIST */
+ 105, 84, 88, 116, (png_byte) '\0', /* iTXt */
+ 112, 67, 65, 76, (png_byte) '\0', /* pCAL */
+ 115, 67, 65, 76, (png_byte) '\0', /* sCAL */
+ 115, 80, 76, 84, (png_byte) '\0', /* sPLT */
+ 116, 73, 77, 69, (png_byte) '\0', /* tIME */
+ };
+ #endif
+
+ ...
+
+ #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+ /* ignore all unknown chunks: */
+ png_set_keep_unknown_chunks(read_ptr, 1, NULL, 0);
+ /* except for vpAg: */
+ png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1);
+ /* also ignore unused known chunks: */
+ png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks,
+ (int)sizeof(unused_chunks)/5);
+ #endif
+
+User limits
+
+The PNG specification allows the width and height of an image to be as
+large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns.
+Since very few applications really need to process such large images,
+we have imposed an arbitrary 1-million limit on rows and columns.
+Larger images will be rejected immediately with a png_error() call. If
+you wish to override this limit, you can use
+
+ png_set_user_limits(png_ptr, width_max, height_max);
+
+to set your own limits, or use width_max = height_max = 0x7fffffffL
+to allow all valid dimensions (libpng may reject some very large images
+anyway because of potential buffer overflow conditions).
+
+You should put this statement after you create the PNG structure and
+before calling png_read_info(), png_read_png(), or png_process_data().
+If you need to retrieve the limits that are being applied, use
+
+ width_max = png_get_user_width_max(png_ptr);
+ height_max = png_get_user_height_max(png_ptr);
+
+The PNG specification sets no limit on the number of ancillary chunks
+allowed in a PNG datastream. You can impose a limit on the total number
+of sPLT, tEXt, iTXt, zTXt, and unknown chunks that will be stored, with
+
+ png_set_chunk_cache_max(png_ptr, user_chunk_cache_max);
+
+where 0x7fffffffL means unlimited. You can retrieve this limit with
+
+ chunk_cache_max = png_get_chunk_cache_max(png_ptr);
+
+This limit also applies to the number of buffers that can be allocated
+by png_decompress_chunk() while decompressing iTXt, zTXt, and iCCP chunks.
+
+You can also set a limit on the amount of memory that a compressed chunk
+other than IDAT can occupy, with
+
+ png_set_chunk_malloc_max(png_ptr, user_chunk_malloc_max);
+
+and you can retrieve the limit with
+
+ chunk_malloc_max = png_get_chunk_malloc_max(png_ptr);
+
+Any chunks that would cause either of these limits to be exceeded will
+be ignored.
+
+The high-level read interface
+
+At this point there are two ways to proceed; through the high-level
+read interface, or through a sequence of low-level read operations.
+You can use the high-level interface if (a) you are willing to read
+the entire image into memory, and (b) the input transformations
+you want to do are limited to the following set:
+
+ PNG_TRANSFORM_IDENTITY No transformation
+ PNG_TRANSFORM_STRIP_16 Strip 16-bit samples to
+ 8 bits
+ PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel
+ PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit
+ samples to bytes
+ PNG_TRANSFORM_PACKSWAP Change order of packed
+ pixels to LSB first
+ PNG_TRANSFORM_EXPAND Perform set_expand()
+ PNG_TRANSFORM_INVERT_MONO Invert monochrome images
+ PNG_TRANSFORM_SHIFT Normalize pixels to the
+ sBIT depth
+ PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA
+ to BGRA
+ PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA
+ to AG
+ PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity
+ to transparency
+ PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
+ PNG_TRANSFORM_GRAY_TO_RGB Expand grayscale samples
+ to RGB (or GA to RGBA)
+
+(This excludes setting a background color, doing gamma transformation,
+quantizing, and setting filler.) If this is the case, simply do this:
+
+ png_read_png(png_ptr, info_ptr, png_transforms, NULL)
+
+where png_transforms is an integer containing the bitwise OR of some
+set of transformation flags. This call is equivalent to png_read_info(),
+followed the set of transformations indicated by the transform mask,
+then png_read_image(), and finally png_read_end().
+
+(The final parameter of this call is not yet used. Someday it might point
+to transformation parameters required by some future input transform.)
+
+You must use png_transforms and not call any png_set_transform() functions
+when you use png_read_png().
+
+After you have called png_read_png(), you can retrieve the image data
+with
+
+ row_pointers = png_get_rows(png_ptr, info_ptr);
+
+where row_pointers is an array of pointers to the pixel data for each row:
+
+ png_bytep row_pointers[height];
+
+If you know your image size and pixel size ahead of time, you can allocate
+row_pointers prior to calling png_read_png() with
+
+ if (height > PNG_UINT_32_MAX/png_sizeof(png_byte))
+ png_error (png_ptr,
+ "Image is too tall to process in memory");
+ if (width > PNG_UINT_32_MAX/pixel_size)
+ png_error (png_ptr,
+ "Image is too wide to process in memory");
+ row_pointers = png_malloc(png_ptr,
+ height*png_sizeof(png_bytep));
+ for (int i=0; i<height, i++)
+ row_pointers[i]=NULL; /* security precaution */
+ for (int i=0; i<height, i++)
+ row_pointers[i]=png_malloc(png_ptr,
+ width*pixel_size);
+ png_set_rows(png_ptr, info_ptr, &row_pointers);
+
+Alternatively you could allocate your image in one big block and define
+row_pointers[i] to point into the proper places in your block.
+
+If you use png_set_rows(), the application is responsible for freeing
+row_pointers (and row_pointers[i], if they were separately allocated).
+
+If you don't allocate row_pointers ahead of time, png_read_png() will
+do it, and it'll be free'ed when you call png_destroy_*().
+
+The low-level read interface
+
+If you are going the low-level route, you are now ready to read all
+the file information up to the actual image data. You do this with a
+call to png_read_info().
+
+ png_read_info(png_ptr, info_ptr);
+
+This will process all chunks up to but not including the image data.
+
+Querying the info structure
+
+Functions are used to get the information from the info_ptr once it
+has been read. Note that these fields may not be completely filled
+in until png_read_end() has read the chunk data following the image.
+
+ png_get_IHDR(png_ptr, info_ptr, &width, &height,
+ &bit_depth, &color_type, &interlace_type,
+ &compression_type, &filter_method);
+
+ width - holds the width of the image
+ in pixels (up to 2^31).
+ height - holds the height of the image
+ in pixels (up to 2^31).
+ bit_depth - holds the bit depth of one of the
+ image channels. (valid values are
+ 1, 2, 4, 8, 16 and depend also on
+ the color_type. See also
+ significant bits (sBIT) below).
+ color_type - describes which color/alpha channels
+ are present.
+ PNG_COLOR_TYPE_GRAY
+ (bit depths 1, 2, 4, 8, 16)
+ PNG_COLOR_TYPE_GRAY_ALPHA
+ (bit depths 8, 16)
+ PNG_COLOR_TYPE_PALETTE
+ (bit depths 1, 2, 4, 8)
+ PNG_COLOR_TYPE_RGB
+ (bit_depths 8, 16)
+ PNG_COLOR_TYPE_RGB_ALPHA
+ (bit_depths 8, 16)
+
+ PNG_COLOR_MASK_PALETTE
+ PNG_COLOR_MASK_COLOR
+ PNG_COLOR_MASK_ALPHA
+
+ filter_method - (must be PNG_FILTER_TYPE_BASE
+ for PNG 1.0, and can also be
+ PNG_INTRAPIXEL_DIFFERENCING if
+ the PNG datastream is embedded in
+ a MNG-1.0 datastream)
+ compression_type - (must be PNG_COMPRESSION_TYPE_BASE
+ for PNG 1.0)
+ interlace_type - (PNG_INTERLACE_NONE or
+ PNG_INTERLACE_ADAM7)
+
+ Any or all of interlace_type, compression_type, or
+ filter_method can be NULL if you are
+ not interested in their values.
+
+ Note that png_get_IHDR() returns 32-bit data into
+ the application's width and height variables.
+ This is an unsafe situation if these are 16-bit
+ variables. In such situations, the
+ png_get_image_width() and png_get_image_height()
+ functions described below are safer.
+
+ width = png_get_image_width(png_ptr,
+ info_ptr);
+ height = png_get_image_height(png_ptr,
+ info_ptr);
+ bit_depth = png_get_bit_depth(png_ptr,
+ info_ptr);
+ color_type = png_get_color_type(png_ptr,
+ info_ptr);
+ filter_method = png_get_filter_type(png_ptr,
+ info_ptr);
+ compression_type = png_get_compression_type(png_ptr,
+ info_ptr);
+ interlace_type = png_get_interlace_type(png_ptr,
+ info_ptr);
+
+ channels = png_get_channels(png_ptr, info_ptr);
+ channels - number of channels of info for the
+ color type (valid values are 1 (GRAY,
+ PALETTE), 2 (GRAY_ALPHA), 3 (RGB),
+ 4 (RGB_ALPHA or RGB + filler byte))
+ rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+ rowbytes - number of bytes needed to hold a row
+
+ signature = png_get_signature(png_ptr, info_ptr);
+ signature - holds the signature read from the
+ file (if any). The data is kept in
+ the same offset it would be if the
+ whole signature were read (i.e. if an
+ application had already read in 4
+ bytes of signature before starting
+ libpng, the remaining 4 bytes would
+ be in signature[4] through signature[7]
+ (see png_set_sig_bytes())).
+
+These are also important, but their validity depends on whether the chunk
+has been read. The png_get_valid(png_ptr, info_ptr, PNG_INFO_<chunk>) and
+png_get_<chunk>(png_ptr, info_ptr, ...) functions return non-zero if the
+data has been read, or zero if it is missing. The parameters to the
+png_get_<chunk> are set directly if they are simple data types, or a
+pointer into the info_ptr is returned for any complex types.
+
+ png_get_PLTE(png_ptr, info_ptr, &palette,
+ &num_palette);
+ palette - the palette for the file
+ (array of png_color)
+ num_palette - number of entries in the palette
+
+ png_get_gAMA(png_ptr, info_ptr, &gamma);
+ gamma - the gamma the file is written
+ at (PNG_INFO_gAMA)
+
+ png_get_sRGB(png_ptr, info_ptr, &srgb_intent);
+ srgb_intent - the rendering intent (PNG_INFO_sRGB)
+ The presence of the sRGB chunk
+ means that the pixel data is in the
+ sRGB color space. This chunk also
+ implies specific values of gAMA and
+ cHRM.
+
+ png_get_iCCP(png_ptr, info_ptr, &name,
+ &compression_type, &profile, &proflen);
+ name - The profile name.
+ compression - The compression type; always
+ PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+ You may give NULL to this argument to
+ ignore it.
+ profile - International Color Consortium color
+ profile data. May contain NULs.
+ proflen - length of profile data in bytes.
+
+ png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+ sig_bit - the number of significant bits for
+ (PNG_INFO_sBIT) each of the gray,
+ red, green, and blue channels,
+ whichever are appropriate for the
+ given color type (png_color_16)
+
+ png_get_tRNS(png_ptr, info_ptr, &trans_alpha,
+ &num_trans, &trans_color);
+ trans_alpha - array of alpha (transparency)
+ entries for palette (PNG_INFO_tRNS)
+ trans_color - graylevel or color sample values of
+ the single transparent color for
+ non-paletted images (PNG_INFO_tRNS)
+ num_trans - number of transparent entries
+ (PNG_INFO_tRNS)
+
+ png_get_hIST(png_ptr, info_ptr, &hist);
+ (PNG_INFO_hIST)
+ hist - histogram of palette (array of
+ png_uint_16)
+
+ png_get_tIME(png_ptr, info_ptr, &mod_time);
+ mod_time - time image was last modified
+ (PNG_VALID_tIME)
+
+ png_get_bKGD(png_ptr, info_ptr, &background);
+ background - background color (PNG_VALID_bKGD)
+ valid 16-bit red, green and blue
+ values, regardless of color_type
+
+ num_comments = png_get_text(png_ptr, info_ptr,
+ &text_ptr, &num_text);
+ num_comments - number of comments
+ text_ptr - array of png_text holding image
+ comments
+ text_ptr[i].compression - type of compression used
+ on "text" PNG_TEXT_COMPRESSION_NONE
+ PNG_TEXT_COMPRESSION_zTXt
+ PNG_ITXT_COMPRESSION_NONE
+ PNG_ITXT_COMPRESSION_zTXt
+ text_ptr[i].key - keyword for comment. Must contain
+ 1-79 characters.
+ text_ptr[i].text - text comments for current
+ keyword. Can be empty.
+ text_ptr[i].text_length - length of text string,
+ after decompression, 0 for iTXt
+ text_ptr[i].itxt_length - length of itxt string,
+ after decompression, 0 for tEXt/zTXt
+ text_ptr[i].lang - language of comment (empty
+ string for unknown).
+ text_ptr[i].lang_key - keyword in UTF-8
+ (empty string for unknown).
+ Note that the itxt_length, lang, and lang_key
+ members of the text_ptr structure only exist
+ when the library is built with iTXt chunk support.
+
+ num_text - number of comments (same as
+ num_comments; you can put NULL here
+ to avoid the duplication)
+ Note while png_set_text() will accept text, language,
+ and translated keywords that can be NULL pointers, the
+ structure returned by png_get_text will always contain
+ regular zero-terminated C strings. They might be
+ empty strings but they will never be NULL pointers.
+
+ num_spalettes = png_get_sPLT(png_ptr, info_ptr,
+ &palette_ptr);
+ palette_ptr - array of palette structures holding
+ contents of one or more sPLT chunks
+ read.
+ num_spalettes - number of sPLT chunks read.
+
+ png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y,
+ &unit_type);
+ offset_x - positive offset from the left edge
+ of the screen
+ offset_y - positive offset from the top edge
+ of the screen
+ unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
+
+ png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y,
+ &unit_type);
+ res_x - pixels/unit physical resolution in
+ x direction
+ res_y - pixels/unit physical resolution in
+ x direction
+ unit_type - PNG_RESOLUTION_UNKNOWN,
+ PNG_RESOLUTION_METER
+
+ png_get_sCAL(png_ptr, info_ptr, &unit, &width,
+ &height)
+ unit - physical scale units (an integer)
+ width - width of a pixel in physical scale units
+ height - height of a pixel in physical scale units
+ (width and height are doubles)
+
+ png_get_sCAL_s(png_ptr, info_ptr, &unit, &width,
+ &height)
+ unit - physical scale units (an integer)
+ width - width of a pixel in physical scale units
+ height - height of a pixel in physical scale units
+ (width and height are strings like "2.54")
+
+ num_unknown_chunks = png_get_unknown_chunks(png_ptr,
+ info_ptr, &unknowns)
+ unknowns - array of png_unknown_chunk
+ structures holding unknown chunks
+ unknowns[i].name - name of unknown chunk
+ unknowns[i].data - data of unknown chunk
+ unknowns[i].size - size of unknown chunk's data
+ unknowns[i].location - position of chunk in file
+
+ The value of "i" corresponds to the order in which the
+ chunks were read from the PNG file or inserted with the
+ png_set_unknown_chunks() function.
+
+The data from the pHYs chunk can be retrieved in several convenient
+forms:
+
+ res_x = png_get_x_pixels_per_meter(png_ptr,
+ info_ptr)
+ res_y = png_get_y_pixels_per_meter(png_ptr,
+ info_ptr)
+ res_x_and_y = png_get_pixels_per_meter(png_ptr,
+ info_ptr)
+ res_x = png_get_x_pixels_per_inch(png_ptr,
+ info_ptr)
+ res_y = png_get_y_pixels_per_inch(png_ptr,
+ info_ptr)
+ res_x_and_y = png_get_pixels_per_inch(png_ptr,
+ info_ptr)
+ aspect_ratio = png_get_pixel_aspect_ratio(png_ptr,
+ info_ptr)
+
+ (Each of these returns 0 [signifying "unknown"] if
+ the data is not present or if res_x is 0;
+ res_x_and_y is 0 if res_x != res_y)
+
+The data from the oFFs chunk can be retrieved in several convenient
+forms:
+
+ x_offset = png_get_x_offset_microns(png_ptr, info_ptr);
+ y_offset = png_get_y_offset_microns(png_ptr, info_ptr);
+ x_offset = png_get_x_offset_inches(png_ptr, info_ptr);
+ y_offset = png_get_y_offset_inches(png_ptr, info_ptr);
+
+ (Each of these returns 0 [signifying "unknown" if both
+ x and y are 0] if the data is not present or if the
+ chunk is present but the unit is the pixel)
+
+For more information, see the png_info definition in png.h and the
+PNG specification for chunk contents. Be careful with trusting
+rowbytes, as some of the transformations could increase the space
+needed to hold a row (expand, filler, gray_to_rgb, etc.).
+See png_read_update_info(), below.
+
+A quick word about text_ptr and num_text. PNG stores comments in
+keyword/text pairs, one pair per chunk, with no limit on the number
+of text chunks, and a 2^31 byte limit on their size. While there are
+suggested keywords, there is no requirement to restrict the use to these
+strings. It is strongly suggested that keywords and text be sensible
+to humans (that's the point), so don't use abbreviations. Non-printing
+symbols are not allowed. See the PNG specification for more details.
+There is also no requirement to have text after the keyword.
+
+Keywords should be limited to 79 Latin-1 characters without leading or
+trailing spaces, but non-consecutive spaces are allowed within the
+keyword. It is possible to have the same keyword any number of times.
+The text_ptr is an array of png_text structures, each holding a
+pointer to a language string, a pointer to a keyword and a pointer to
+a text string. The text string, language code, and translated
+keyword may be empty or NULL pointers. The keyword/text
+pairs are put into the array in the order that they are received.
+However, some or all of the text chunks may be after the image, so, to
+make sure you have read all the text chunks, don't mess with these
+until after you read the stuff after the image. This will be
+mentioned again below in the discussion that goes with png_read_end().
+
+Input transformations
+
+After you've read the header information, you can set up the library
+to handle any special transformations of the image data. The various
+ways to transform the data will be described in the order that they
+should occur. This is important, as some of these change the color
+type and/or bit depth of the data, and some others only work on
+certain color types and bit depths. Even though each transformation
+checks to see if it has data that it can do something with, you should
+make sure to only enable a transformation if it will be valid for the
+data. For example, don't swap red and blue on grayscale data.
+
+The colors used for the background and transparency values should be
+supplied in the same format/depth as the current image data. They
+are stored in the same format/depth as the image data in a bKGD or tRNS
+chunk, so this is what libpng expects for this data. The colors are
+transformed to keep in sync with the image data when an application
+calls the png_read_update_info() routine (see below).
+
+Data will be decoded into the supplied row buffers packed into bytes
+unless the library has been told to transform it into another format.
+For example, 4 bit/pixel paletted or grayscale data will be returned
+2 pixels/byte with the leftmost pixel in the high-order bits of the
+byte, unless png_set_packing() is called. 8-bit RGB data will be stored
+in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
+is called to insert filler bytes, either before or after each RGB triplet.
+16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
+byte of the color value first, unless png_set_strip_16() is called to
+transform it to regular RGB RGB triplets, or png_set_filler() or
+png_set_add alpha() is called to insert filler bytes, either before or
+after each RRGGBB triplet. Similarly, 8-bit or 16-bit grayscale data can
+be modified with
+png_set_filler(), png_set_add_alpha(), or png_set_strip_16().
+
+The following code transforms grayscale images of less than 8 to 8 bits,
+changes paletted images to RGB, and adds a full alpha channel if there is
+transparency information in a tRNS chunk. This is most useful on
+grayscale images with bit depths of 2 or 4 or if there is a multiple-image
+viewing application that wishes to treat all images in the same way.
+
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ png_set_palette_to_rgb(png_ptr);
+
+ if (color_type == PNG_COLOR_TYPE_GRAY &&
+ bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr);
+
+ if (png_get_valid(png_ptr, info_ptr,
+ PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr);
+
+These three functions are actually aliases for png_set_expand(), added
+in libpng version 1.0.4, with the function names expanded to improve code
+readability. In some future version they may actually do different
+things.
+
+As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
+added. It expands the sample depth without changing tRNS to alpha.
+
+As of libpng version 1.4.4, not all possible expansions are supported.
+
+In the following table, the 01 means grayscale with depth<8, 31 means
+indexed with depth<8, other numerals represent the color type, "T" means
+the tRNS chunk is present, A means an alpha channel is present, and O
+means tRNS or alpha is present but all pixels in the image are opaque.
+
+ FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O
+ TO
+ 01 -
+ 31 -
+ 0 1 -
+ 0T -
+ 0O -
+ 2 GX -
+ 2T -
+ 2O -
+ 3 1 -
+ 3T -
+ 3O -
+ 4A T -
+ 4O -
+ 6A GX TX TX -
+ 6O GX TX -
+
+Within the matrix,
+ "-" means the transformation is not supported.
+ "X" means the transformation is obtained by png_set_expand().
+ "1" means the transformation is obtained by
+ png_set_expand_gray_1_2_4_to_8
+ "G" means the transformation is obtained by
+ png_set_gray_to_rgb().
+ "P" means the transformation is obtained by
+ png_set_expand_palette_to_rgb().
+ "T" means the transformation is obtained by
+ png_set_tRNS_to_alpha().
+
+PNG can have files with 16 bits per channel. If you only can handle
+8 bits per channel, this will strip the pixels down to 8 bit.
+
+ if (bit_depth == 16)
+ png_set_strip_16(png_ptr);
+
+If, for some reason, you don't need the alpha channel on an image,
+and you want to remove it rather than combining it with the background
+(but the image author certainly had in mind that you *would* combine
+it with the background, so that's what you should probably do):
+
+ if (color_type & PNG_COLOR_MASK_ALPHA)
+ png_set_strip_alpha(png_ptr);
+
+In PNG files, the alpha channel in an image
+is the level of opacity. If you need the alpha channel in an image to
+be the level of transparency instead of opacity, you can invert the
+alpha channel (or the tRNS chunk data) after it's read, so that 0 is
+fully opaque and 255 (in 8-bit or paletted images) or 65535 (in 16-bit
+images) is fully transparent, with
+
+ png_set_invert_alpha(png_ptr);
+
+PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
+they can, resulting in, for example, 8 pixels per byte for 1 bit
+files. This code expands to 1 pixel per byte without changing the
+values of the pixels:
+
+ if (bit_depth < 8)
+ png_set_packing(png_ptr);
+
+PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels
+stored in a PNG image have been "scaled" or "shifted" up to the next
+higher possible bit depth (e.g. from 5 bits/sample in the range [0,31]
+to 8 bits/sample in the range [0, 255]). However, it is also possible
+to convert the PNG pixel data back to the original bit depth of the
+image. This call reduces the pixels back down to the original bit depth:
+
+ png_color_8p sig_bit;
+
+ if (png_get_sBIT(png_ptr, info_ptr, &sig_bit))
+ png_set_shift(png_ptr, sig_bit);
+
+PNG files store 3-color pixels in red, green, blue order. This code
+changes the storage of the pixels to blue, green, red:
+
+ if (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ png_set_bgr(png_ptr);
+
+PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them
+into 4 or 8 bytes for windowing systems that need them in this format:
+
+ if (color_type == PNG_COLOR_TYPE_RGB)
+ png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
+
+where "filler" is the 8 or 16-bit number to fill with, and the location is
+either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
+you want the filler before the RGB or after. This transformation
+does not affect images that already have full alpha channels. To add an
+opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which
+will generate RGBA pixels.
+
+Note that png_set_filler() does not change the color type. If you want
+to do that, you can add a true alpha channel with
+
+ if (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_GRAY)
+ png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER);
+
+where "filler" contains the alpha value to assign to each pixel.
+This function was added in libpng-1.2.7.
+
+If you are reading an image with an alpha channel, and you need the
+data as ARGB instead of the normal PNG format RGBA:
+
+ if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ png_set_swap_alpha(png_ptr);
+
+For some uses, you may want a grayscale image to be represented as
+RGB. This code will do that conversion:
+
+ if (color_type == PNG_COLOR_TYPE_GRAY ||
+ color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ png_set_gray_to_rgb(png_ptr);
+
+Conversely, you can convert an RGB or RGBA image to grayscale or grayscale
+with alpha.
+
+ if (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ png_set_rgb_to_gray_fixed(png_ptr, error_action,
+ int red_weight, int green_weight);
+
+ error_action = 1: silently do the conversion
+ error_action = 2: issue a warning if the original
+ image has any pixel where
+ red != green or red != blue
+ error_action = 3: issue an error and abort the
+ conversion if the original
+ image has any pixel where
+ red != green or red != blue
+
+ red_weight: weight of red component times 100000
+ green_weight: weight of green component times 100000
+ If either weight is negative, default
+ weights (21268, 71514) are used.
+
+If you have set error_action = 1 or 2, you can
+later check whether the image really was gray, after processing
+the image rows, with the png_get_rgb_to_gray_status(png_ptr) function.
+It will return a png_byte that is zero if the image was gray or
+1 if there were any non-gray pixels. bKGD and sBIT data
+will be silently converted to grayscale, using the green channel
+data, regardless of the error_action setting.
+
+With red_weight+green_weight<=100000,
+the normalized graylevel is computed:
+
+ int rw = red_weight * 65536;
+ int gw = green_weight * 65536;
+ int bw = 65536 - (rw + gw);
+ gray = (rw*red + gw*green + bw*blue)/65536;
+
+The default values approximate those recommended in the Charles
+Poynton's Color FAQ, <http://www.inforamp.net/~poynton/>
+Copyright (c) 1998-01-04 Charles Poynton <poynton at inforamp.net>
+
+ Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+
+Libpng approximates this with
+
+ Y = 0.21268 * R + 0.7151 * G + 0.07217 * B
+
+which can be expressed with integers as
+
+ Y = (6969 * R + 23434 * G + 2365 * B)/32768
+
+The calculation is done in a linear colorspace, if the image gamma
+is known.
+
+If you have a grayscale and you are using png_set_expand_depth(),
+png_set_expand(), or png_set_gray_to_rgb to change to truecolor or to
+a higher bit-depth, you must either supply the background color as a gray
+value at the original file bit-depth (need_expand = 1) or else supply the
+background color as an RGB triplet at the final, expanded bit depth
+(need_expand = 0). Similarly, if you are reading a paletted image, you
+must either supply the background color as a palette index (need_expand = 1)
+or as an RGB triplet that may or may not be in the palette (need_expand = 0).
+
+ png_color_16 my_background;
+ png_color_16p image_background;
+
+ if (png_get_bKGD(png_ptr, info_ptr, &image_background))
+ png_set_background(png_ptr, image_background,
+ PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+ else
+ png_set_background(png_ptr, &my_background,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
+
+The png_set_background() function tells libpng to composite images
+with alpha or simple transparency against the supplied background
+color. If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
+you may use this color, or supply another color more suitable for
+the current display (e.g., the background color from a web page). You
+need to tell libpng whether the color is in the gamma space of the
+display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file
+(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one
+that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't
+know why anyone would use this, but it's here).
+
+To properly display PNG images on any kind of system, the application needs
+to know what the display gamma is. Ideally, the user will know this, and
+the application will allow them to set it. One method of allowing the user
+to set the display gamma separately for each system is to check for a
+SCREEN_GAMMA or DISPLAY_GAMMA environment variable, which will hopefully be
+correctly set.
+
+Note that display_gamma is the overall gamma correction required to produce
+pleasing results, which depends on the lighting conditions in the surrounding
+environment. In a dim or brightly lit room, no compensation other than
+the physical gamma exponent of the monitor is needed, while in a dark room
+a slightly smaller exponent is better.
+
+ double gamma, screen_gamma;
+
+ if (/* We have a user-defined screen
+ gamma value */)
+ {
+ screen_gamma = user_defined_screen_gamma;
+ }
+ /* One way that applications can share the same
+ screen gamma value */
+ else if ((gamma_str = getenv("SCREEN_GAMMA"))
+ != NULL)
+ {
+ screen_gamma = (double)atof(gamma_str);
+ }
+ /* If we don't have another value */
+ else
+ {
+ screen_gamma = 2.2; /* A good guess for a
+ PC monitor in a bright office or a dim room */
+ screen_gamma = 2.0; /* A good guess for a
+ PC monitor in a dark room */
+ screen_gamma = 1.7 or 1.0; /* A good
+ guess for Mac systems */
+ }
+
+The png_set_gamma() function handles gamma transformations of the data.
+Pass both the file gamma and the current screen_gamma. If the file does
+not have a gamma value, you can pass one anyway if you have an idea what
+it is (usually 0.45455 is a good guess for GIF images on PCs). Note
+that file gammas are inverted from screen gammas. See the discussions
+on gamma in the PNG specification for an excellent description of what
+gamma is, and why all applications should support it. It is strongly
+recommended that PNG viewers support gamma correction.
+
+ if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+ png_set_gamma(png_ptr, screen_gamma, gamma);
+ else
+ png_set_gamma(png_ptr, screen_gamma, 0.45455);
+
+If you need to reduce an RGB file to a paletted file, or if a paletted
+file has more entries then will fit on your screen, png_set_quantize()
+will do that. Note that this is a simple match dither that merely
+finds the closest color available. This should work fairly well with
+optimized palettes, and fairly badly with linear color cubes. If you
+pass a palette that is larger then maximum_colors, the file will
+reduce the number of colors in the palette so it will fit into
+maximum_colors. If there is a histogram, it will use it to make
+more intelligent choices when reducing the palette. If there is no
+histogram, it may not do as good a job.
+
+ if (color_type & PNG_COLOR_MASK_COLOR)
+ {
+ if (png_get_valid(png_ptr, info_ptr,
+ PNG_INFO_PLTE))
+ {
+ png_uint_16p histogram = NULL;
+
+ png_get_hIST(png_ptr, info_ptr,
+ &histogram);
+ png_set_quantize(png_ptr, palette, num_palette,
+ max_screen_colors, histogram, 1);
+ }
+ else
+ {
+ png_color std_color_cube[MAX_SCREEN_COLORS] =
+ { ... colors ... };
+
+ png_set_quantize(png_ptr, std_color_cube,
+ MAX_SCREEN_COLORS, MAX_SCREEN_COLORS,
+ NULL,0);
+ }
+ }
+
+PNG files describe monochrome as black being zero and white being one.
+The following code will reverse this (make black be one and white be
+zero):
+
+ if (bit_depth == 1 && color_type == PNG_COLOR_TYPE_GRAY)
+ png_set_invert_mono(png_ptr);
+
+This function can also be used to invert grayscale and gray-alpha images:
+
+ if (color_type == PNG_COLOR_TYPE_GRAY ||
+ color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ png_set_invert_mono(png_ptr);
+
+PNG files store 16 bit pixels in network byte order (big-endian,
+ie. most significant bits first). This code changes the storage to the
+other way (little-endian, i.e. least significant bits first, the
+way PCs store them):
+
+ if (bit_depth == 16)
+ png_set_swap(png_ptr);
+
+If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you
+need to change the order the pixels are packed into bytes, you can use:
+
+ if (bit_depth < 8)
+ png_set_packswap(png_ptr);
+
+Finally, you can write your own transformation function if none of
+the existing ones meets your needs. This is done by setting a callback
+with
+
+ png_set_read_user_transform_fn(png_ptr,
+ read_transform_fn);
+
+You must supply the function
+
+ void read_transform_fn(png_ptr ptr, row_info_ptr
+ row_info, png_bytep data)
+
+See pngtest.c for a working example. Your function will be called
+after all of the other transformations have been processed.
+
+You can also set up a pointer to a user structure for use by your
+callback function, and you can inform libpng that your transform
+function will change the number of channels or bit depth with the
+function
+
+ png_set_user_transform_info(png_ptr, user_ptr,
+ user_depth, user_channels);
+
+The user's application, not libpng, is responsible for allocating and
+freeing any memory required for the user structure.
+
+You can retrieve the pointer via the function
+png_get_user_transform_ptr(). For example:
+
+ voidp read_user_transform_ptr =
+ png_get_user_transform_ptr(png_ptr);
+
+The last thing to handle is interlacing; this is covered in detail below,
+but you must call the function here if you want libpng to handle expansion
+of the interlaced image.
+
+ number_of_passes = png_set_interlace_handling(png_ptr);
+
+After setting the transformations, libpng can update your png_info
+structure to reflect any transformations you've requested with this
+call. This is most useful to update the info structure's rowbytes
+field so you can use it to allocate your image memory. This function
+will also update your palette with the correct screen_gamma and
+background if these have been given with the calls above.
+
+ png_read_update_info(png_ptr, info_ptr);
+
+After you call png_read_update_info(), you can allocate any
+memory you need to hold the image. The row data is simply
+raw byte data for all forms of images. As the actual allocation
+varies among applications, no example will be given. If you
+are allocating one large chunk, you will need to build an
+array of pointers to each row, as it will be needed for some
+of the functions below.
+
+Reading image data
+
+After you've allocated memory, you can read the image data.
+The simplest way to do this is in one function call. If you are
+allocating enough memory to hold the whole image, you can just
+call png_read_image() and libpng will read in all the image data
+and put it in the memory area supplied. You will need to pass in
+an array of pointers to each row.
+
+This function automatically handles interlacing, so you don't need
+to call png_set_interlace_handling() or call this function multiple
+times, or any of that other stuff necessary with png_read_rows().
+
+ png_read_image(png_ptr, row_pointers);
+
+where row_pointers is:
+
+ png_bytep row_pointers[height];
+
+You can point to void or char or whatever you use for pixels.
+
+If you don't want to read in the whole image at once, you can
+use png_read_rows() instead. If there is no interlacing (check
+interlace_type == PNG_INTERLACE_NONE), this is simple:
+
+ png_read_rows(png_ptr, row_pointers, NULL,
+ number_of_rows);
+
+where row_pointers is the same as in the png_read_image() call.
+
+If you are doing this just one row at a time, you can do this with
+a single row_pointer instead of an array of row_pointers:
+
+ png_bytep row_pointer = row;
+ png_read_row(png_ptr, row_pointer, NULL);
+
+If the file is interlaced (interlace_type != 0 in the IHDR chunk), things
+get somewhat harder. The only current (PNG Specification version 1.2)
+interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7)
+is a somewhat complicated 2D interlace scheme, known as Adam7, that
+breaks down an image into seven smaller images of varying size, based
+on an 8x8 grid.
+
+libpng can fill out those images or it can give them to you "as is".
+If you want them filled out, there are two ways to do that. The one
+mentioned in the PNG specification is to expand each pixel to cover
+those pixels that have not been read yet (the "rectangle" method).
+This results in a blocky image for the first pass, which gradually
+smooths out as more pixels are read. The other method is the "sparkle"
+method, where pixels are drawn only in their final locations, with the
+rest of the image remaining whatever colors they were initialized to
+before the start of the read. The first method usually looks better,
+but tends to be slower, as there are more pixels to put in the rows.
+
+If you don't want libpng to handle the interlacing details, just call
+png_read_rows() seven times to read in all seven images. Each of the
+images is a valid image by itself, or they can all be combined on an
+8x8 grid to form a single image (although if you intend to combine them
+you would be far better off using the libpng interlace handling).
+
+The first pass will return an image 1/8 as wide as the entire image
+(every 8th column starting in column 0) and 1/8 as high as the original
+(every 8th row starting in row 0), the second will be 1/8 as wide
+(starting in column 4) and 1/8 as high (also starting in row 0). The
+third pass will be 1/4 as wide (every 4th pixel starting in column 0) and
+1/8 as high (every 8th row starting in row 4), and the fourth pass will
+be 1/4 as wide and 1/4 as high (every 4th column starting in column 2,
+and every 4th row starting in row 0). The fifth pass will return an
+image 1/2 as wide, and 1/4 as high (starting at column 0 and row 2),
+while the sixth pass will be 1/2 as wide and 1/2 as high as the original
+(starting in column 1 and row 0). The seventh and final pass will be as
+wide as the original, and 1/2 as high, containing all of the odd
+numbered scanlines. Phew!
+
+If you want libpng to expand the images, call this before calling
+png_start_read_image() or png_read_update_info():
+
+ if (interlace_type == PNG_INTERLACE_ADAM7)
+ number_of_passes
+ = png_set_interlace_handling(png_ptr);
+
+This will return the number of passes needed. Currently, this
+is seven, but may change if another interlace type is added.
+This function can be called even if the file is not interlaced,
+where it will return one pass.
+
+If you are not going to display the image after each pass, but are
+going to wait until the entire image is read in, use the sparkle
+effect. This effect is faster and the end result of either method
+is exactly the same. If you are planning on displaying the image
+after each pass, the "rectangle" effect is generally considered the
+better looking one.
+
+If you only want the "sparkle" effect, just call png_read_rows() as
+normal, with the third parameter NULL. Make sure you make pass over
+the image number_of_passes times, and you don't change the data in the
+rows between calls. You can change the locations of the data, just
+not the data. Each pass only writes the pixels appropriate for that
+pass, and assumes the data from previous passes is still valid.
+
+ png_read_rows(png_ptr, row_pointers, NULL,
+ number_of_rows);
+
+If you only want the first effect (the rectangles), do the same as
+before except pass the row buffer in the third parameter, and leave
+the second parameter NULL.
+
+ png_read_rows(png_ptr, NULL, row_pointers,
+ number_of_rows);
+
+Finishing a sequential read
+
+After you are finished reading the image through the
+low-level interface, you can finish reading the file. If you are
+interested in comments or time, which may be stored either before or
+after the image data, you should pass the separate png_info struct if
+you want to keep the comments from before and after the image
+separate. If you are not interested, you can pass NULL.
+
+ png_read_end(png_ptr, end_info);
+
+When you are done, you can free all memory allocated by libpng like this:
+
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ &end_info);
+
+It is also possible to individually free the info_ptr members that
+point to libpng-allocated storage with the following function:
+
+ png_free_data(png_ptr, info_ptr, mask, seq)
+ mask - identifies data to be freed, a mask
+ containing the bitwise OR of one or
+ more of
+ PNG_FREE_PLTE, PNG_FREE_TRNS,
+ PNG_FREE_HIST, PNG_FREE_ICCP,
+ PNG_FREE_PCAL, PNG_FREE_ROWS,
+ PNG_FREE_SCAL, PNG_FREE_SPLT,
+ PNG_FREE_TEXT, PNG_FREE_UNKN,
+ or simply PNG_FREE_ALL
+ seq - sequence number of item to be freed
+ (-1 for all items)
+
+This function may be safely called when the relevant storage has
+already been freed, or has not yet been allocated, or was allocated
+by the user and not by libpng, and will in those cases do nothing.
+The "seq" parameter is ignored if only one item of the selected data
+type, such as PLTE, is allowed. If "seq" is not -1, and multiple items
+are allowed for the data type identified in the mask, such as text or
+sPLT, only the n'th item in the structure is freed, where n is "seq".
+
+The default behavior is only to free data that was allocated internally
+by libpng. This can be changed, so that libpng will not free the data,
+or so that it will free data that was allocated by the user with png_malloc()
+or png_zalloc() and passed in via a png_set_*() function, with
+
+ png_data_freer(png_ptr, info_ptr, freer, mask)
+ mask - which data elements are affected
+ same choices as in png_free_data()
+ freer - one of
+ PNG_DESTROY_WILL_FREE_DATA
+ PNG_SET_WILL_FREE_DATA
+ PNG_USER_WILL_FREE_DATA
+
+This function only affects data that has already been allocated.
+You can call this function after reading the PNG data but before calling
+any png_set_*() functions, to control whether the user or the png_set_*()
+function is responsible for freeing any existing data that might be present,
+and again after the png_set_*() functions to control whether the user
+or png_destroy_*() is supposed to free the data. When the user assumes
+responsibility for libpng-allocated data, the application must use
+png_free() to free it, and when the user transfers responsibility to libpng
+for data that the user has allocated, the user must have used png_malloc()
+or png_zalloc() to allocate it.
+
+If you allocated your row_pointers in a single block, as suggested above in
+the description of the high level read interface, you must not transfer
+responsibility for freeing it to the png_set_rows or png_read_destroy function,
+because they would also try to free the individual row_pointers[i].
+
+If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
+separately, do not transfer responsibility for freeing text_ptr to libpng,
+because when libpng fills a png_text structure it combines these members with
+the key member, and png_free_data() will free only text_ptr.key. Similarly,
+if you transfer responsibility for free'ing text_ptr from libpng to your
+application, your application must not separately free those members.
+
+The png_free_data() function will turn off the "valid" flag for anything
+it frees. If you need to turn the flag off for a chunk that was freed by
+your application instead of by libpng, you can use
+
+ png_set_invalid(png_ptr, info_ptr, mask);
+ mask - identifies the chunks to be made invalid,
+ containing the bitwise OR of one or
+ more of
+ PNG_INFO_gAMA, PNG_INFO_sBIT,
+ PNG_INFO_cHRM, PNG_INFO_PLTE,
+ PNG_INFO_tRNS, PNG_INFO_bKGD,
+ PNG_INFO_hIST, PNG_INFO_pHYs,
+ PNG_INFO_oFFs, PNG_INFO_tIME,
+ PNG_INFO_pCAL, PNG_INFO_sRGB,
+ PNG_INFO_iCCP, PNG_INFO_sPLT,
+ PNG_INFO_sCAL, PNG_INFO_IDAT
+
+For a more compact example of reading a PNG image, see the file example.c.
+
+Reading PNG files progressively
+
+The progressive reader is slightly different then the non-progressive
+reader. Instead of calling png_read_info(), png_read_rows(), and
+png_read_end(), you make one call to png_process_data(), which calls
+callbacks when it has the info, a row, or the end of the image. You
+set up these callbacks with png_set_progressive_read_fn(). You don't
+have to worry about the input/output functions of libpng, as you are
+giving the library the data directly in png_process_data(). I will
+assume that you have read the section on reading PNG files above,
+so I will only highlight the differences (although I will show
+all of the code).
+
+png_structp png_ptr;
+png_infop info_ptr;
+
+ /* An example code fragment of how you would
+ initialize the progressive reader in your
+ application. */
+ int
+ initialize_png_reader()
+ {
+ png_ptr = png_create_read_struct
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ user_error_fn, user_warning_fn);
+ if (!png_ptr)
+ return (ERROR);
+ info_ptr = png_create_info_struct(png_ptr);
+ if (!info_ptr)
+ {
+ png_destroy_read_struct(&png_ptr, (png_infopp)NULL,
+ (png_infopp)NULL);
+ return (ERROR);
+ }
+
+ if (setjmp(png_jmpbuf(png_ptr)))
+ {
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ (png_infopp)NULL);
+ return (ERROR);
+ }
+
+ /* This one's new. You can provide functions
+ to be called when the header info is valid,
+ when each row is completed, and when the image
+ is finished. If you aren't using all functions,
+ you can specify NULL parameters. Even when all
+ three functions are NULL, you need to call
+ png_set_progressive_read_fn(). You can use
+ any struct as the user_ptr (cast to a void pointer
+ for the function call), and retrieve the pointer
+ from inside the callbacks using the function
+
+ png_get_progressive_ptr(png_ptr);
+
+ which will return a void pointer, which you have
+ to cast appropriately.
+ */
+ png_set_progressive_read_fn(png_ptr, (void *)user_ptr,
+ info_callback, row_callback, end_callback);
+
+ return 0;
+ }
+
+ /* A code fragment that you call as you receive blocks
+ of data */
+ int
+ process_data(png_bytep buffer, png_uint_32 length)
+ {
+ if (setjmp(png_jmpbuf(png_ptr)))
+ {
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ (png_infopp)NULL);
+ return (ERROR);
+ }
+
+ /* This one's new also. Simply give it a chunk
+ of data from the file stream (in order, of
+ course). On machines with segmented memory
+ models machines, don't give it any more than
+ 64K. The library seems to run fine with sizes
+ of 4K. Although you can give it much less if
+ necessary (I assume you can give it chunks of
+ 1 byte, I haven't tried less then 256 bytes
+ yet). When this function returns, you may
+ want to display any rows that were generated
+ in the row callback if you don't already do
+ so there.
+ */
+ png_process_data(png_ptr, info_ptr, buffer, length);
+ return 0;
+ }
+
+ /* This function is called (as set by
+ png_set_progressive_read_fn() above) when enough data
+ has been supplied so all of the header has been
+ read.
+ */
+ void
+ info_callback(png_structp png_ptr, png_infop info)
+ {
+ /* Do any setup here, including setting any of
+ the transformations mentioned in the Reading
+ PNG files section. For now, you _must_ call
+ either png_start_read_image() or
+ png_read_update_info() after all the
+ transformations are set (even if you don't set
+ any). You may start getting rows before
+ png_process_data() returns, so this is your
+ last chance to prepare for that.
+ */
+ }
+
+ /* This function is called when each row of image
+ data is complete */
+ void
+ row_callback(png_structp png_ptr, png_bytep new_row,
+ png_uint_32 row_num, int pass)
+ {
+ /* If the image is interlaced, and you turned
+ on the interlace handler, this function will
+ be called for every row in every pass. Some
+ of these rows will not be changed from the
+ previous pass. When the row is not changed,
+ the new_row variable will be NULL. The rows
+ and passes are called in order, so you don't
+ really need the row_num and pass, but I'm
+ supplying them because it may make your life
+ easier.
+
+ For the non-NULL rows of interlaced images,
+ you must call png_progressive_combine_row()
+ passing in the row and the old row. You can
+ call this function for NULL rows (it will just
+ return) and for non-interlaced images (it just
+ does the memcpy for you) if it will make the
+ code easier. Thus, you can just do this for
+ all cases:
+ */
+
+ png_progressive_combine_row(png_ptr, old_row,
+ new_row);
+
+ /* where old_row is what was displayed for
+ previously for the row. Note that the first
+ pass (pass == 0, really) will completely cover
+ the old row, so the rows do not have to be
+ initialized. After the first pass (and only
+ for interlaced images), you will have to pass
+ the current row, and the function will combine
+ the old row and the new row.
+ */
+ }
+
+ void
+ end_callback(png_structp png_ptr, png_infop info)
+ {
+ /* This function is called after the whole image
+ has been read, including any chunks after the
+ image (up to and including the IEND). You
+ will usually have the same info chunk as you
+ had in the header, although some data may have
+ been added to the comments and time fields.
+
+ Most people won't do much here, perhaps setting
+ a flag that marks the image as finished.
+ */
+ }
+
+
+
+IV. Writing
+
+Much of this is very similar to reading. However, everything of
+importance is repeated here, so you won't have to constantly look
+back up in the reading section to understand writing.
+
+Setup
+
+You will want to do the I/O initialization before you get into libpng,
+so if it doesn't work, you don't have anything to undo. If you are not
+using the standard I/O functions, you will need to replace them with
+custom writing functions. See the discussion under Customizing libpng.
+
+ FILE *fp = fopen(file_name, "wb");
+ if (!fp)
+ {
+ return (ERROR);
+ }
+
+Next, png_struct and png_info need to be allocated and initialized.
+As these can be both relatively large, you may not want to store these
+on the stack, unless you have stack space to spare. Of course, you
+will want to check if they return NULL. If you are also reading,
+you won't want to name your read structure and your write structure
+both "png_ptr"; you can call them anything you like, such as
+"read_ptr" and "write_ptr". Look at pngtest.c, for example.
+
+ png_structp png_ptr = png_create_write_struct
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ user_error_fn, user_warning_fn);
+ if (!png_ptr)
+ return (ERROR);
+
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+ if (!info_ptr)
+ {
+ png_destroy_write_struct(&png_ptr,
+ (png_infopp)NULL);
+ return (ERROR);
+ }
+
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_write_struct_2() instead of png_create_write_struct():
+
+ png_structp png_ptr = png_create_write_struct_2
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ user_error_fn, user_warning_fn, (png_voidp)
+ user_mem_ptr, user_malloc_fn, user_free_fn);
+
+After you have these structures, you will need to set up the
+error handling. When libpng encounters an error, it expects to
+longjmp() back to your routine. Therefore, you will need to call
+setjmp() and pass the png_jmpbuf(png_ptr). If you
+write the file from different routines, you will need to update
+the png_jmpbuf(png_ptr) every time you enter a new routine that will
+call a png_*() function. See your documentation of setjmp/longjmp
+for your compiler for more information on setjmp/longjmp. See
+the discussion on libpng error handling in the Customizing Libpng
+section below for more information on the libpng error handling.
+
+ if (setjmp(png_jmpbuf(png_ptr)))
+ {
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+ fclose(fp);
+ return (ERROR);
+ }
+ ...
+ return;
+
+If you would rather avoid the complexity of setjmp/longjmp issues,
+you can compile libpng with PNG_NO_SETJMP, in which case
+errors will result in a call to PNG_ABORT() which defaults to abort().
+
+You can #define PNG_ABORT() to a function that does something
+more useful than abort(), as long as your function does not
+return.
+
+Now you need to set up the output code. The default for libpng is to
+use the C function fwrite(). If you use this, you will need to pass a
+valid FILE * in the function png_init_io(). Be sure that the file is
+opened in binary mode. Again, if you wish to handle writing data in
+another way, see the discussion on libpng I/O handling in the Customizing
+Libpng section below.
+
+ png_init_io(png_ptr, fp);
+
+If you are embedding your PNG into a datastream such as MNG, and don't
+want libpng to write the 8-byte signature, or if you have already
+written the signature in your application, use
+
+ png_set_sig_bytes(png_ptr, 8);
+
+to inform libpng that it should not write a signature.
+
+Write callbacks
+
+At this point, you can set up a callback function that will be
+called after each row has been written, which you can use to control
+a progress meter or the like. It's demonstrated in pngtest.c.
+You must supply a function
+
+ void write_row_callback(png_ptr, png_uint_32 row,
+ int pass);
+ {
+ /* put your code here */
+ }
+
+(You can give it another name that you like instead of "write_row_callback")
+
+To inform libpng about your function, use
+
+ png_set_write_status_fn(png_ptr, write_row_callback);
+
+You now have the option of modifying how the compression library will
+run. The following functions are mainly for testing, but may be useful
+in some cases, like if you need to write PNG files extremely fast and
+are willing to give up some compression, or if you want to get the
+maximum possible compression at the expense of slower writing. If you
+have no special needs in this area, let the library do what it wants by
+not calling this function at all, as it has been tuned to deliver a good
+speed/compression ratio. The second parameter to png_set_filter() is
+the filter method, for which the only valid values are 0 (as of the
+July 1999 PNG specification, version 1.2) or 64 (if you are writing
+a PNG datastream that is to be embedded in a MNG datastream). The third
+parameter is a flag that indicates which filter type(s) are to be tested
+for each scanline. See the PNG specification for details on the specific
+filter types.
+
+
+ /* turn on or off filtering, and/or choose
+ specific filters. You can use either a single
+ PNG_FILTER_VALUE_NAME or the bitwise OR of one
+ or more PNG_FILTER_NAME masks. */
+ png_set_filter(png_ptr, 0,
+ PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE |
+ PNG_FILTER_SUB | PNG_FILTER_VALUE_SUB |
+ PNG_FILTER_UP | PNG_FILTER_VALUE_UP |
+ PNG_FILTER_AVG | PNG_FILTER_VALUE_AVG |
+ PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH|
+ PNG_ALL_FILTERS);
+
+If an application
+wants to start and stop using particular filters during compression,
+it should start out with all of the filters (to ensure that the previous
+row of pixels will be stored in case it's needed later), and then add
+and remove them after the start of compression.
+
+If you are writing a PNG datastream that is to be embedded in a MNG
+datastream, the second parameter can be either 0 or 64.
+
+The png_set_compression_*() functions interface to the zlib compression
+library, and should mostly be ignored unless you really know what you are
+doing. The only generally useful call is png_set_compression_level()
+which changes how much time zlib spends on trying to compress the image
+data. See the Compression Library (zlib.h and algorithm.txt, distributed
+with zlib) for details on the compression levels.
+
+ /* set the zlib compression level */
+ png_set_compression_level(png_ptr,
+ Z_BEST_COMPRESSION);
+
+ /* set other zlib parameters */
+ png_set_compression_mem_level(png_ptr, 8);
+ png_set_compression_strategy(png_ptr,
+ Z_DEFAULT_STRATEGY);
+ png_set_compression_window_bits(png_ptr, 15);
+ png_set_compression_method(png_ptr, 8);
+ png_set_compression_buffer_size(png_ptr, 8192)
+
+extern PNG_EXPORT(void,png_set_zbuf_size)
+
+Setting the contents of info for output
+
+You now need to fill in the png_info structure with all the data you
+wish to write before the actual image. Note that the only thing you
+are allowed to write after the image is the text chunks and the time
+chunk (as of PNG Specification 1.2, anyway). See png_write_end() and
+the latest PNG specification for more information on that. If you
+wish to write them before the image, fill them in now, and flag that
+data as being valid. If you want to wait until after the data, don't
+fill them until png_write_end(). For all the fields in png_info and
+their data types, see png.h. For explanations of what the fields
+contain, see the PNG specification.
+
+Some of the more important parts of the png_info are:
+
+ png_set_IHDR(png_ptr, info_ptr, width, height,
+ bit_depth, color_type, interlace_type,
+ compression_type, filter_method)
+ width - holds the width of the image
+ in pixels (up to 2^31).
+ height - holds the height of the image
+ in pixels (up to 2^31).
+ bit_depth - holds the bit depth of one of the
+ image channels.
+ (valid values are 1, 2, 4, 8, 16
+ and depend also on the
+ color_type. See also significant
+ bits (sBIT) below).
+ color_type - describes which color/alpha
+ channels are present.
+ PNG_COLOR_TYPE_GRAY
+ (bit depths 1, 2, 4, 8, 16)
+ PNG_COLOR_TYPE_GRAY_ALPHA
+ (bit depths 8, 16)
+ PNG_COLOR_TYPE_PALETTE
+ (bit depths 1, 2, 4, 8)
+ PNG_COLOR_TYPE_RGB
+ (bit_depths 8, 16)
+ PNG_COLOR_TYPE_RGB_ALPHA
+ (bit_depths 8, 16)
+
+ PNG_COLOR_MASK_PALETTE
+ PNG_COLOR_MASK_COLOR
+ PNG_COLOR_MASK_ALPHA
+
+ interlace_type - PNG_INTERLACE_NONE or
+ PNG_INTERLACE_ADAM7
+ compression_type - (must be
+ PNG_COMPRESSION_TYPE_DEFAULT)
+ filter_method - (must be PNG_FILTER_TYPE_DEFAULT
+ or, if you are writing a PNG to
+ be embedded in a MNG datastream,
+ can also be
+ PNG_INTRAPIXEL_DIFFERENCING)
+
+If you call png_set_IHDR(), the call must appear before any of the
+other png_set_*() functions, because they might require access to some of
+the IHDR settings. The remaining png_set_*() functions can be called
+in any order.
+
+If you wish, you can reset the compression_type, interlace_type, or
+filter_method later by calling png_set_IHDR() again; if you do this, the
+width, height, bit_depth, and color_type must be the same in each call.
+
+ png_set_PLTE(png_ptr, info_ptr, palette,
+ num_palette);
+ palette - the palette for the file
+ (array of png_color)
+ num_palette - number of entries in the palette
+
+ png_set_gAMA(png_ptr, info_ptr, gamma);
+ gamma - the gamma the image was created
+ at (PNG_INFO_gAMA)
+
+ png_set_sRGB(png_ptr, info_ptr, srgb_intent);
+ srgb_intent - the rendering intent
+ (PNG_INFO_sRGB) The presence of
+ the sRGB chunk means that the pixel
+ data is in the sRGB color space.
+ This chunk also implies specific
+ values of gAMA and cHRM. Rendering
+ intent is the CSS-1 property that
+ has been defined by the International
+ Color Consortium
+ (http://www.color.org).
+ It can be one of
+ PNG_sRGB_INTENT_SATURATION,
+ PNG_sRGB_INTENT_PERCEPTUAL,
+ PNG_sRGB_INTENT_ABSOLUTE, or
+ PNG_sRGB_INTENT_RELATIVE.
+
+
+ png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr,
+ srgb_intent);
+ srgb_intent - the rendering intent
+ (PNG_INFO_sRGB) The presence of the
+ sRGB chunk means that the pixel
+ data is in the sRGB color space.
+ This function also causes gAMA and
+ cHRM chunks with the specific values
+ that are consistent with sRGB to be
+ written.
+
+ png_set_iCCP(png_ptr, info_ptr, name, compression_type,
+ profile, proflen);
+ name - The profile name.
+ compression - The compression type; always
+ PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+ You may give NULL to this argument to
+ ignore it.
+ profile - International Color Consortium color
+ profile data. May contain NULs.
+ proflen - length of profile data in bytes.
+
+ png_set_sBIT(png_ptr, info_ptr, sig_bit);
+ sig_bit - the number of significant bits for
+ (PNG_INFO_sBIT) each of the gray, red,
+ green, and blue channels, whichever are
+ appropriate for the given color type
+ (png_color_16)
+
+ png_set_tRNS(png_ptr, info_ptr, trans_alpha,
+ num_trans, trans_color);
+ trans_alpha - array of alpha (transparency)
+ entries for palette (PNG_INFO_tRNS)
+ trans_color - graylevel or color sample values
+ (in order red, green, blue) of the
+ single transparent color for
+ non-paletted images (PNG_INFO_tRNS)
+ num_trans - number of transparent entries
+ (PNG_INFO_tRNS)
+
+ png_set_hIST(png_ptr, info_ptr, hist);
+ (PNG_INFO_hIST)
+ hist - histogram of palette (array of
+ png_uint_16)
+
+ png_set_tIME(png_ptr, info_ptr, mod_time);
+ mod_time - time image was last modified
+ (PNG_VALID_tIME)
+
+ png_set_bKGD(png_ptr, info_ptr, background);
+ background - background color (PNG_VALID_bKGD)
+
+ png_set_text(png_ptr, info_ptr, text_ptr, num_text);
+ text_ptr - array of png_text holding image
+ comments
+ text_ptr[i].compression - type of compression used
+ on "text" PNG_TEXT_COMPRESSION_NONE
+ PNG_TEXT_COMPRESSION_zTXt
+ PNG_ITXT_COMPRESSION_NONE
+ PNG_ITXT_COMPRESSION_zTXt
+ text_ptr[i].key - keyword for comment. Must contain
+ 1-79 characters.
+ text_ptr[i].text - text comments for current
+ keyword. Can be NULL or empty.
+ text_ptr[i].text_length - length of text string,
+ after decompression, 0 for iTXt
+ text_ptr[i].itxt_length - length of itxt string,
+ after decompression, 0 for tEXt/zTXt
+ text_ptr[i].lang - language of comment (NULL or
+ empty for unknown).
+ text_ptr[i].translated_keyword - keyword in UTF-8 (NULL
+ or empty for unknown).
+ Note that the itxt_length, lang, and lang_key
+ members of the text_ptr structure only exist
+ when the library is built with iTXt chunk support.
+
+ num_text - number of comments
+
+ png_set_sPLT(png_ptr, info_ptr, &palette_ptr,
+ num_spalettes);
+ palette_ptr - array of png_sPLT_struct structures
+ to be added to the list of palettes
+ in the info structure.
+ num_spalettes - number of palette structures to be
+ added.
+
+ png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y,
+ unit_type);
+ offset_x - positive offset from the left
+ edge of the screen
+ offset_y - positive offset from the top
+ edge of the screen
+ unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
+
+ png_set_pHYs(png_ptr, info_ptr, res_x, res_y,
+ unit_type);
+ res_x - pixels/unit physical resolution
+ in x direction
+ res_y - pixels/unit physical resolution
+ in y direction
+ unit_type - PNG_RESOLUTION_UNKNOWN,
+ PNG_RESOLUTION_METER
+
+ png_set_sCAL(png_ptr, info_ptr, unit, width, height)
+ unit - physical scale units (an integer)
+ width - width of a pixel in physical scale units
+ height - height of a pixel in physical scale units
+ (width and height are doubles)
+
+ png_set_sCAL_s(png_ptr, info_ptr, unit, width, height)
+ unit - physical scale units (an integer)
+ width - width of a pixel in physical scale units
+ height - height of a pixel in physical scale units
+ (width and height are strings like "2.54")
+
+ png_set_unknown_chunks(png_ptr, info_ptr, &unknowns,
+ num_unknowns)
+ unknowns - array of png_unknown_chunk
+ structures holding unknown chunks
+ unknowns[i].name - name of unknown chunk
+ unknowns[i].data - data of unknown chunk
+ unknowns[i].size - size of unknown chunk's data
+ unknowns[i].location - position to write chunk in file
+ 0: do not write chunk
+ PNG_HAVE_IHDR: before PLTE
+ PNG_HAVE_PLTE: before IDAT
+ PNG_AFTER_IDAT: after IDAT
+
+The "location" member is set automatically according to
+what part of the output file has already been written.
+You can change its value after calling png_set_unknown_chunks()
+as demonstrated in pngtest.c. Within each of the "locations",
+the chunks are sequenced according to their position in the
+structure (that is, the value of "i", which is the order in which
+the chunk was either read from the input file or defined with
+png_set_unknown_chunks).
+
+A quick word about text and num_text. text is an array of png_text
+structures. num_text is the number of valid structures in the array.
+Each png_text structure holds a language code, a keyword, a text value,
+and a compression type.
+
+The compression types have the same valid numbers as the compression
+types of the image data. Currently, the only valid number is zero.
+However, you can store text either compressed or uncompressed, unlike
+images, which always have to be compressed. So if you don't want the
+text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE.
+Because tEXt and zTXt chunks don't have a language field, if you
+specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt
+any language code or translated keyword will not be written out.
+
+Until text gets around 1000 bytes, it is not worth compressing it.
+After the text has been written out to the file, the compression type
+is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR,
+so that it isn't written out again at the end (in case you are calling
+png_write_end() with the same struct.
+
+The keywords that are given in the PNG Specification are:
+
+ Title Short (one line) title or
+ caption for image
+ Author Name of image's creator
+ Description Description of image (possibly long)
+ Copyright Copyright notice
+ Creation Time Time of original image creation
+ (usually RFC 1123 format, see below)
+ Software Software used to create the image
+ Disclaimer Legal disclaimer
+ Warning Warning of nature of content
+ Source Device used to create the image
+ Comment Miscellaneous comment; conversion
+ from other image format
+
+The keyword-text pairs work like this. Keywords should be short
+simple descriptions of what the comment is about. Some typical
+keywords are found in the PNG specification, as is some recommendations
+on keywords. You can repeat keywords in a file. You can even write
+some text before the image and some after. For example, you may want
+to put a description of the image before the image, but leave the
+disclaimer until after, so viewers working over modem connections
+don't have to wait for the disclaimer to go over the modem before
+they start seeing the image. Finally, keywords should be full
+words, not abbreviations. Keywords and text are in the ISO 8859-1
+(Latin-1) character set (a superset of regular ASCII) and can not
+contain NUL characters, and should not contain control or other
+unprintable characters. To make the comments widely readable, stick
+with basic ASCII, and avoid machine specific character set extensions
+like the IBM-PC character set. The keyword must be present, but
+you can leave off the text string on non-compressed pairs.
+Compressed pairs must have a text string, as only the text string
+is compressed anyway, so the compression would be meaningless.
+
+PNG supports modification time via the png_time structure. Two
+conversion routines are provided, png_convert_from_time_t() for
+time_t and png_convert_from_struct_tm() for struct tm. The
+time_t routine uses gmtime(). You don't have to use either of
+these, but if you wish to fill in the png_time structure directly,
+you should provide the time in universal time (GMT) if possible
+instead of your local time. Note that the year number is the full
+year (e.g. 1998, rather than 98 - PNG is year 2000 compliant!), and
+that months start with 1.
+
+If you want to store the time of the original image creation, you should
+use a plain tEXt chunk with the "Creation Time" keyword. This is
+necessary because the "creation time" of a PNG image is somewhat vague,
+depending on whether you mean the PNG file, the time the image was
+created in a non-PNG format, a still photo from which the image was
+scanned, or possibly the subject matter itself. In order to facilitate
+machine-readable dates, it is recommended that the "Creation Time"
+tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
+although this isn't a requirement. Unlike the tIME chunk, the
+"Creation Time" tEXt chunk is not expected to be automatically changed
+by the software. To facilitate the use of RFC 1123 dates, a function
+png_convert_to_rfc1123(png_timep) is provided to convert from PNG
+time to an RFC 1123 format string.
+
+Writing unknown chunks
+
+You can use the png_set_unknown_chunks function to queue up chunks
+for writing. You give it a chunk name, raw data, and a size; that's
+all there is to it. The chunks will be written by the next following
+png_write_info_before_PLTE, png_write_info, or png_write_end function.
+Any chunks previously read into the info structure's unknown-chunk
+list will also be written out in a sequence that satisfies the PNG
+specification's ordering rules.
+
+The high-level write interface
+
+At this point there are two ways to proceed; through the high-level
+write interface, or through a sequence of low-level write operations.
+You can use the high-level interface if your image data is present
+in the info structure. All defined output
+transformations are permitted, enabled by the following masks.
+
+ PNG_TRANSFORM_IDENTITY No transformation
+ PNG_TRANSFORM_PACKING Pack 1, 2 and 4-bit samples
+ PNG_TRANSFORM_PACKSWAP Change order of packed
+ pixels to LSB first
+ PNG_TRANSFORM_INVERT_MONO Invert monochrome images
+ PNG_TRANSFORM_SHIFT Normalize pixels to the
+ sBIT depth
+ PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA
+ to BGRA
+ PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA
+ to AG
+ PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity
+ to transparency
+ PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
+ PNG_TRANSFORM_STRIP_FILLER Strip out filler
+ bytes (deprecated).
+ PNG_TRANSFORM_STRIP_FILLER_BEFORE Strip out leading
+ filler bytes
+ PNG_TRANSFORM_STRIP_FILLER_AFTER Strip out trailing
+ filler bytes
+
+If you have valid image data in the info structure (you can use
+png_set_rows() to put image data in the info structure), simply do this:
+
+ png_write_png(png_ptr, info_ptr, png_transforms, NULL)
+
+where png_transforms is an integer containing the bitwise OR of some set of
+transformation flags. This call is equivalent to png_write_info(),
+followed the set of transformations indicated by the transform mask,
+then png_write_image(), and finally png_write_end().
+
+(The final parameter of this call is not yet used. Someday it might point
+to transformation parameters required by some future output transform.)
+
+You must use png_transforms and not call any png_set_transform() functions
+when you use png_write_png().
+
+The low-level write interface
+
+If you are going the low-level route instead, you are now ready to
+write all the file information up to the actual image data. You do
+this with a call to png_write_info().
+
+ png_write_info(png_ptr, info_ptr);
+
+Note that there is one transformation you may need to do before
+png_write_info(). In PNG files, the alpha channel in an image is the
+level of opacity. If your data is supplied as a level of transparency,
+you can invert the alpha channel before you write it, so that 0 is
+fully transparent and 255 (in 8-bit or paletted images) or 65535
+(in 16-bit images) is fully opaque, with
+
+ png_set_invert_alpha(png_ptr);
+
+This must appear before png_write_info() instead of later with the
+other transformations because in the case of paletted images the tRNS
+chunk data has to be inverted before the tRNS chunk is written. If
+your image is not a paletted image, the tRNS data (which in such cases
+represents a single color to be rendered as transparent) won't need to
+be changed, and you can safely do this transformation after your
+png_write_info() call.
+
+If you need to write a private chunk that you want to appear before
+the PLTE chunk when PLTE is present, you can write the PNG info in
+two steps, and insert code to write your own chunk between them:
+
+ png_write_info_before_PLTE(png_ptr, info_ptr);
+ png_set_unknown_chunks(png_ptr, info_ptr, ...);
+ png_write_info(png_ptr, info_ptr);
+
+After you've written the file information, you can set up the library
+to handle any special transformations of the image data. The various
+ways to transform the data will be described in the order that they
+should occur. This is important, as some of these change the color
+type and/or bit depth of the data, and some others only work on
+certain color types and bit depths. Even though each transformation
+checks to see if it has data that it can do something with, you should
+make sure to only enable a transformation if it will be valid for the
+data. For example, don't swap red and blue on grayscale data.
+
+PNG files store RGB pixels packed into 3 or 6 bytes. This code tells
+the library to strip input data that has 4 or 8 bytes per pixel down
+to 3 or 6 bytes (or strip 2 or 4-byte grayscale+filler data to 1 or 2
+bytes per pixel).
+
+ png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+
+where the 0 is unused, and the location is either PNG_FILLER_BEFORE or
+PNG_FILLER_AFTER, depending upon whether the filler byte in the pixel
+is stored XRGB or RGBX.
+
+PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
+they can, resulting in, for example, 8 pixels per byte for 1 bit files.
+If the data is supplied at 1 pixel per byte, use this code, which will
+correctly pack the pixels into a single byte:
+
+ png_set_packing(png_ptr);
+
+PNG files reduce possible bit depths to 1, 2, 4, 8, and 16. If your
+data is of another bit depth, you can write an sBIT chunk into the
+file so that decoders can recover the original data if desired.
+
+ /* Set the true bit depth of the image data */
+ if (color_type & PNG_COLOR_MASK_COLOR)
+ {
+ sig_bit.red = true_bit_depth;
+ sig_bit.green = true_bit_depth;
+ sig_bit.blue = true_bit_depth;
+ }
+ else
+ {
+ sig_bit.gray = true_bit_depth;
+ }
+ if (color_type & PNG_COLOR_MASK_ALPHA)
+ {
+ sig_bit.alpha = true_bit_depth;
+ }
+
+ png_set_sBIT(png_ptr, info_ptr, &sig_bit);
+
+If the data is stored in the row buffer in a bit depth other than
+one supported by PNG (e.g. 3 bit data in the range 0-7 for a 4-bit PNG),
+this will scale the values to appear to be the correct bit depth as
+is required by PNG.
+
+ png_set_shift(png_ptr, &sig_bit);
+
+PNG files store 16 bit pixels in network byte order (big-endian,
+ie. most significant bits first). This code would be used if they are
+supplied the other way (little-endian, i.e. least significant bits
+first, the way PCs store them):
+
+ if (bit_depth > 8)
+ png_set_swap(png_ptr);
+
+If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you
+need to change the order the pixels are packed into bytes, you can use:
+
+ if (bit_depth < 8)
+ png_set_packswap(png_ptr);
+
+PNG files store 3 color pixels in red, green, blue order. This code
+would be used if they are supplied as blue, green, red:
+
+ png_set_bgr(png_ptr);
+
+PNG files describe monochrome as black being zero and white being
+one. This code would be used if the pixels are supplied with this reversed
+(black being one and white being zero):
+
+ png_set_invert_mono(png_ptr);
+
+Finally, you can write your own transformation function if none of
+the existing ones meets your needs. This is done by setting a callback
+with
+
+ png_set_write_user_transform_fn(png_ptr,
+ write_transform_fn);
+
+You must supply the function
+
+ void write_transform_fn(png_ptr ptr, row_info_ptr
+ row_info, png_bytep data)
+
+See pngtest.c for a working example. Your function will be called
+before any of the other transformations are processed.
+
+You can also set up a pointer to a user structure for use by your
+callback function.
+
+ png_set_user_transform_info(png_ptr, user_ptr, 0, 0);
+
+The user_channels and user_depth parameters of this function are ignored
+when writing; you can set them to zero as shown.
+
+You can retrieve the pointer via the function png_get_user_transform_ptr().
+For example:
+
+ voidp write_user_transform_ptr =
+ png_get_user_transform_ptr(png_ptr);
+
+It is possible to have libpng flush any pending output, either manually,
+or automatically after a certain number of lines have been written. To
+flush the output stream a single time call:
+
+ png_write_flush(png_ptr);
+
+and to have libpng flush the output stream periodically after a certain
+number of scanlines have been written, call:
+
+ png_set_flush(png_ptr, nrows);
+
+Note that the distance between rows is from the last time png_write_flush()
+was called, or the first row of the image if it has never been called.
+So if you write 50 lines, and then png_set_flush 25, it will flush the
+output on the next scanline, and every 25 lines thereafter, unless
+png_write_flush() is called before 25 more lines have been written.
+If nrows is too small (less than about 10 lines for a 640 pixel wide
+RGB image) the image compression may decrease noticeably (although this
+may be acceptable for real-time applications). Infrequent flushing will
+only degrade the compression performance by a few percent over images
+that do not use flushing.
+
+Writing the image data
+
+That's it for the transformations. Now you can write the image data.
+The simplest way to do this is in one function call. If you have the
+whole image in memory, you can just call png_write_image() and libpng
+will write the image. You will need to pass in an array of pointers to
+each row. This function automatically handles interlacing, so you don't
+need to call png_set_interlace_handling() or call this function multiple
+times, or any of that other stuff necessary with png_write_rows().
+
+ png_write_image(png_ptr, row_pointers);
+
+where row_pointers is:
+
+ png_byte *row_pointers[height];
+
+You can point to void or char or whatever you use for pixels.
+
+If you don't want to write the whole image at once, you can
+use png_write_rows() instead. If the file is not interlaced,
+this is simple:
+
+ png_write_rows(png_ptr, row_pointers,
+ number_of_rows);
+
+row_pointers is the same as in the png_write_image() call.
+
+If you are just writing one row at a time, you can do this with
+a single row_pointer instead of an array of row_pointers:
+
+ png_bytep row_pointer = row;
+
+ png_write_row(png_ptr, row_pointer);
+
+When the file is interlaced, things can get a good deal more complicated.
+The only currently (as of the PNG Specification version 1.2, dated July
+1999) defined interlacing scheme for PNG files is the "Adam7" interlace
+scheme, that breaks down an image into seven smaller images of varying
+size. libpng will build these images for you, or you can do them
+yourself. If you want to build them yourself, see the PNG specification
+for details of which pixels to write when.
+
+If you don't want libpng to handle the interlacing details, just
+use png_set_interlace_handling() and call png_write_rows() the
+correct number of times to write all seven sub-images.
+
+If you want libpng to build the sub-images, call this before you start
+writing any rows:
+
+ number_of_passes =
+ png_set_interlace_handling(png_ptr);
+
+This will return the number of passes needed. Currently, this is seven,
+but may change if another interlace type is added.
+
+Then write the complete image number_of_passes times.
+
+ png_write_rows(png_ptr, row_pointers,
+ number_of_rows);
+
+As some of these rows are not used, and thus return immediately, you may
+want to read about interlacing in the PNG specification, and only update
+the rows that are actually used.
+
+Finishing a sequential write
+
+After you are finished writing the image, you should finish writing
+the file. If you are interested in writing comments or time, you should
+pass an appropriately filled png_info pointer. If you are not interested,
+you can pass NULL.
+
+ png_write_end(png_ptr, info_ptr);
+
+When you are done, you can free all memory used by libpng like this:
+
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+
+It is also possible to individually free the info_ptr members that
+point to libpng-allocated storage with the following function:
+
+ png_free_data(png_ptr, info_ptr, mask, seq)
+ mask - identifies data to be freed, a mask
+ containing the bitwise OR of one or
+ more of
+ PNG_FREE_PLTE, PNG_FREE_TRNS,
+ PNG_FREE_HIST, PNG_FREE_ICCP,
+ PNG_FREE_PCAL, PNG_FREE_ROWS,
+ PNG_FREE_SCAL, PNG_FREE_SPLT,
+ PNG_FREE_TEXT, PNG_FREE_UNKN,
+ or simply PNG_FREE_ALL
+ seq - sequence number of item to be freed
+ (-1 for all items)
+
+This function may be safely called when the relevant storage has
+already been freed, or has not yet been allocated, or was allocated
+by the user and not by libpng, and will in those cases do nothing.
+The "seq" parameter is ignored if only one item of the selected data
+type, such as PLTE, is allowed. If "seq" is not -1, and multiple items
+are allowed for the data type identified in the mask, such as text or
+sPLT, only the n'th item in the structure is freed, where n is "seq".
+
+If you allocated data such as a palette that you passed in to libpng
+with png_set_*, you must not free it until just before the call to
+png_destroy_write_struct().
+
+The default behavior is only to free data that was allocated internally
+by libpng. This can be changed, so that libpng will not free the data,
+or so that it will free data that was allocated by the user with png_malloc()
+or png_zalloc() and passed in via a png_set_*() function, with
+
+ png_data_freer(png_ptr, info_ptr, freer, mask)
+ mask - which data elements are affected
+ same choices as in png_free_data()
+ freer - one of
+ PNG_DESTROY_WILL_FREE_DATA
+ PNG_SET_WILL_FREE_DATA
+ PNG_USER_WILL_FREE_DATA
+
+For example, to transfer responsibility for some data from a read structure
+to a write structure, you could use
+
+ png_data_freer(read_ptr, read_info_ptr,
+ PNG_USER_WILL_FREE_DATA,
+ PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
+ png_data_freer(write_ptr, write_info_ptr,
+ PNG_DESTROY_WILL_FREE_DATA,
+ PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
+
+thereby briefly reassigning responsibility for freeing to the user but
+immediately afterwards reassigning it once more to the write_destroy
+function. Having done this, it would then be safe to destroy the read
+structure and continue to use the PLTE, tRNS, and hIST data in the write
+structure.
+
+This function only affects data that has already been allocated.
+You can call this function before calling after the png_set_*() functions
+to control whether the user or png_destroy_*() is supposed to free the data.
+When the user assumes responsibility for libpng-allocated data, the
+application must use
+png_free() to free it, and when the user transfers responsibility to libpng
+for data that the user has allocated, the user must have used png_malloc()
+or png_zalloc() to allocate it.
+
+If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
+separately, do not transfer responsibility for freeing text_ptr to libpng,
+because when libpng fills a png_text structure it combines these members with
+the key member, and png_free_data() will free only text_ptr.key. Similarly,
+if you transfer responsibility for free'ing text_ptr from libpng to your
+application, your application must not separately free those members.
+For a more compact example of writing a PNG image, see the file example.c.
+
+V. Modifying/Customizing libpng:
+
+There are two issues here. The first is changing how libpng does
+standard things like memory allocation, input/output, and error handling.
+The second deals with more complicated things like adding new chunks,
+adding new transformations, and generally changing how libpng works.
+Both of those are compile-time issues; that is, they are generally
+determined at the time the code is written, and there is rarely a need
+to provide the user with a means of changing them.
+
+Memory allocation, input/output, and error handling
+
+All of the memory allocation, input/output, and error handling in libpng
+goes through callbacks that are user-settable. The default routines are
+in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively. To change
+these functions, call the appropriate png_set_*_fn() function.
+
+Memory allocation is done through the functions png_malloc(), png_calloc(),
+and png_free(). These currently just call the standard C functions.
+png_calloc() calls png_malloc() and then png_memset() to clear the newly
+allocated memory to zero. If your pointers can't access more then 64K
+at a time, you will want to set MAXSEG_64K in zlib.h. Since it is
+unlikely that the method of handling memory allocation on a platform
+will change between applications, these functions must be modified in
+the library at compile time. If you prefer to use a different method
+of allocating and freeing data, you can use png_create_read_struct_2() or
+png_create_write_struct_2() to register your own functions as described
+above. These functions also provide a void pointer that can be retrieved
+via
+
+ mem_ptr=png_get_mem_ptr(png_ptr);
+
+Your replacement memory functions must have prototypes as follows:
+
+ png_voidp malloc_fn(png_structp png_ptr,
+ png_alloc_size_t size);
+ void free_fn(png_structp png_ptr, png_voidp ptr);
+
+Your malloc_fn() must return NULL in case of failure. The png_malloc()
+function will normally call png_error() if it receives a NULL from the
+system memory allocator or from your replacement malloc_fn().
+
+Your free_fn() will never be called with a NULL ptr, since libpng's
+png_free() checks for NULL before calling free_fn().
+
+Input/Output in libpng is done through png_read() and png_write(),
+which currently just call fread() and fwrite(). The FILE * is stored in
+png_struct and is initialized via png_init_io(). If you wish to change
+the method of I/O, the library supplies callbacks that you can set
+through the function png_set_read_fn() and png_set_write_fn() at run
+time, instead of calling the png_init_io() function. These functions
+also provide a void pointer that can be retrieved via the function
+png_get_io_ptr(). For example:
+
+ png_set_read_fn(png_structp read_ptr,
+ voidp read_io_ptr, png_rw_ptr read_data_fn)
+
+ png_set_write_fn(png_structp write_ptr,
+ voidp write_io_ptr, png_rw_ptr write_data_fn,
+ png_flush_ptr output_flush_fn);
+
+ voidp read_io_ptr = png_get_io_ptr(read_ptr);
+ voidp write_io_ptr = png_get_io_ptr(write_ptr);
+
+The replacement I/O functions must have prototypes as follows:
+
+ void user_read_data(png_structp png_ptr,
+ png_bytep data, png_size_t length);
+ void user_write_data(png_structp png_ptr,
+ png_bytep data, png_size_t length);
+ void user_flush_data(png_structp png_ptr);
+
+The user_read_data() function is responsible for detecting and
+handling end-of-data errors.
+
+Supplying NULL for the read, write, or flush functions sets them back
+to using the default C stream functions, which expect the io_ptr to
+point to a standard *FILE structure. It is probably a mistake
+to use NULL for one of write_data_fn and output_flush_fn but not both
+of them, unless you have built libpng with PNG_NO_WRITE_FLUSH defined.
+It is an error to read from a write stream, and vice versa.
+
+Error handling in libpng is done through png_error() and png_warning().
+Errors handled through png_error() are fatal, meaning that png_error()
+should never return to its caller. Currently, this is handled via
+setjmp() and longjmp() (unless you have compiled libpng with
+PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()),
+but you could change this to do things like exit() if you should wish,
+as long as your function does not return.
+
+On non-fatal errors, png_warning() is called
+to print a warning message, and then control returns to the calling code.
+By default png_error() and png_warning() print a message on stderr via
+fprintf() unless the library is compiled with PNG_NO_CONSOLE_IO defined
+(because you don't want the messages) or PNG_NO_STDIO defined (because
+fprintf() isn't available). If you wish to change the behavior of the error
+functions, you will need to set up your own message callbacks. These
+functions are normally supplied at the time that the png_struct is created.
+It is also possible to redirect errors and warnings to your own replacement
+functions after png_create_*_struct() has been called by calling:
+
+ png_set_error_fn(png_structp png_ptr,
+ png_voidp error_ptr, png_error_ptr error_fn,
+ png_error_ptr warning_fn);
+
+ png_voidp error_ptr = png_get_error_ptr(png_ptr);
+
+If NULL is supplied for either error_fn or warning_fn, then the libpng
+default function will be used, calling fprintf() and/or longjmp() if a
+problem is encountered. The replacement error functions should have
+parameters as follows:
+
+ void user_error_fn(png_structp png_ptr,
+ png_const_charp error_msg);
+ void user_warning_fn(png_structp png_ptr,
+ png_const_charp warning_msg);
+
+The motivation behind using setjmp() and longjmp() is the C++ throw and
+catch exception handling methods. This makes the code much easier to write,
+as there is no need to check every return code of every function call.
+However, there are some uncertainties about the status of local variables
+after a longjmp, so the user may want to be careful about doing anything
+after setjmp returns non-zero besides returning itself. Consult your
+compiler documentation for more details. For an alternative approach, you
+may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net).
+
+Custom chunks
+
+If you need to read or write custom chunks, you may need to get deeper
+into the libpng code. The library now has mechanisms for storing
+and writing chunks of unknown type; you can even declare callbacks
+for custom chunks. However, this may not be good enough if the
+library code itself needs to know about interactions between your
+chunk and existing `intrinsic' chunks.
+
+If you need to write a new intrinsic chunk, first read the PNG
+specification. Acquire a first level of understanding of how it works.
+Pay particular attention to the sections that describe chunk names,
+and look at how other chunks were designed, so you can do things
+similarly. Second, check out the sections of libpng that read and
+write chunks. Try to find a chunk that is similar to yours and use
+it as a template. More details can be found in the comments inside
+the code. It is best to handle unknown chunks in a generic method,
+via callback functions, instead of by modifying libpng functions.
+
+If you wish to write your own transformation for the data, look through
+the part of the code that does the transformations, and check out some of
+the simpler ones to get an idea of how they work. Try to find a similar
+transformation to the one you want to add and copy off of it. More details
+can be found in the comments inside the code itself.
+
+Configuring for 16 bit platforms
+
+You will want to look into zconf.h to tell zlib (and thus libpng) that
+it cannot allocate more then 64K at a time. Even if you can, the memory
+won't be accessible. So limit zlib and libpng to 64K by defining MAXSEG_64K.
+
+Configuring for DOS
+
+For DOS users who only have access to the lower 640K, you will
+have to limit zlib's memory usage via a png_set_compression_mem_level()
+call. See zlib.h or zconf.h in the zlib library for more information.
+
+Configuring for Medium Model
+
+Libpng's support for medium model has been tested on most of the popular
+compilers. Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
+defined, and FAR gets defined to far in pngconf.h, and you should be
+all set. Everything in the library (except for zlib's structure) is
+expecting far data. You must use the typedefs with the p or pp on
+the end for pointers (or at least look at them and be careful). Make
+note that the rows of data are defined as png_bytepp, which is an
+unsigned char far * far *.
+
+Configuring for gui/windowing platforms:
+
+You will need to write new error and warning functions that use the GUI
+interface, as described previously, and set them to be the error and
+warning functions at the time that png_create_*_struct() is called,
+in order to have them available during the structure initialization.
+They can be changed later via png_set_error_fn(). On some compilers,
+you may also have to change the memory allocators (png_malloc, etc.).
+
+Configuring for compiler xxx:
+
+All includes for libpng are in pngconf.h. If you need to add, change
+or delete an include, this is the place to do it.
+The includes that are not needed outside libpng are placed in pngpriv.h,
+which is only used by the routines inside libpng itself.
+The files in libpng proper only include pngpriv.h and png.h, which
+in turn includes pngconf.h.
+
+Configuring zlib:
+
+There are special functions to configure the compression. Perhaps the
+most useful one changes the compression level, which currently uses
+input compression values in the range 0 - 9. The library normally
+uses the default compression level (Z_DEFAULT_COMPRESSION = 6). Tests
+have shown that for a large majority of images, compression values in
+the range 3-6 compress nearly as well as higher levels, and do so much
+faster. For online applications it may be desirable to have maximum speed
+(Z_BEST_SPEED = 1). With versions of zlib after v0.99, you can also
+specify no compression (Z_NO_COMPRESSION = 0), but this would create
+files larger than just storing the raw bitmap. You can specify the
+compression level by calling:
+
+ png_set_compression_level(png_ptr, level);
+
+Another useful one is to reduce the memory level used by the library.
+The memory level defaults to 8, but it can be lowered if you are
+short on memory (running DOS, for example, where you only have 640K).
+Note that the memory level does have an effect on compression; among
+other things, lower levels will result in sections of incompressible
+data being emitted in smaller stored blocks, with a correspondingly
+larger relative overhead of up to 15% in the worst case.
+
+ png_set_compression_mem_level(png_ptr, level);
+
+The other functions are for configuring zlib. They are not recommended
+for normal use and may result in writing an invalid PNG file. See
+zlib.h for more information on what these mean.
+
+ png_set_compression_strategy(png_ptr,
+ strategy);
+ png_set_compression_window_bits(png_ptr,
+ window_bits);
+ png_set_compression_method(png_ptr, method);
+ png_set_compression_buffer_size(png_ptr, size);
+
+Controlling row filtering
+
+If you want to control whether libpng uses filtering or not, which
+filters are used, and how it goes about picking row filters, you
+can call one of these functions. The selection and configuration
+of row filters can have a significant impact on the size and
+encoding speed and a somewhat lesser impact on the decoding speed
+of an image. Filtering is enabled by default for RGB and grayscale
+images (with and without alpha), but not for paletted images nor
+for any images with bit depths less than 8 bits/pixel.
+
+The 'method' parameter sets the main filtering method, which is
+currently only '0' in the PNG 1.2 specification. The 'filters'
+parameter sets which filter(s), if any, should be used for each
+scanline. Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS
+to turn filtering on and off, respectively.
+
+Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB,
+PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise
+ORed together with '|' to specify one or more filters to use.
+These filters are described in more detail in the PNG specification.
+If you intend to change the filter type during the course of writing
+the image, you should start with flags set for all of the filters
+you intend to use so that libpng can initialize its internal
+structures appropriately for all of the filter types. (Note that this
+means the first row must always be adaptively filtered, because libpng
+currently does not allocate the filter buffers until png_write_row()
+is called for the first time.)
+
+ filters = PNG_FILTER_NONE | PNG_FILTER_SUB
+ PNG_FILTER_UP | PNG_FILTER_AVG |
+ PNG_FILTER_PAETH | PNG_ALL_FILTERS;
+
+ png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE,
+ filters);
+ The second parameter can also be
+ PNG_INTRAPIXEL_DIFFERENCING if you are
+ writing a PNG to be embedded in a MNG
+ datastream. This parameter must be the
+ same as the value of filter_method used
+ in png_set_IHDR().
+
+It is also possible to influence how libpng chooses from among the
+available filters. This is done in one or both of two ways - by
+telling it how important it is to keep the same filter for successive
+rows, and by telling it the relative computational costs of the filters.
+
+ double weights[3] = {1.5, 1.3, 1.1},
+ costs[PNG_FILTER_VALUE_LAST] =
+ {1.0, 1.3, 1.3, 1.5, 1.7};
+
+ png_set_filter_heuristics(png_ptr,
+ PNG_FILTER_HEURISTIC_WEIGHTED, 3,
+ weights, costs);
+
+The weights are multiplying factors that indicate to libpng that the
+row filter should be the same for successive rows unless another row filter
+is that many times better than the previous filter. In the above example,
+if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
+"sum of absolute differences" 1.5 x 1.3 times higher than other filters
+and still be chosen, while the NONE filter could have a sum 1.1 times
+higher than other filters and still be chosen. Unspecified weights are
+taken to be 1.0, and the specified weights should probably be declining
+like those above in order to emphasize recent filters over older filters.
+
+The filter costs specify for each filter type a relative decoding cost
+to be considered when selecting row filters. This means that filters
+with higher costs are less likely to be chosen over filters with lower
+costs, unless their "sum of absolute differences" is that much smaller.
+The costs do not necessarily reflect the exact computational speeds of
+the various filters, since this would unduly influence the final image
+size.
+
+Note that the numbers above were invented purely for this example and
+are given only to help explain the function usage. Little testing has
+been done to find optimum values for either the costs or the weights.
+
+Removing unwanted object code
+
+There are a bunch of #define's in pngconf.h that control what parts of
+libpng are compiled. All the defines end in _SUPPORTED. If you are
+never going to use a capability, you can change the #define to #undef
+before recompiling libpng and save yourself code and data space, or
+you can turn off individual capabilities with defines that begin with
+PNG_NO_.
+
+You can also turn all of the transforms and ancillary chunk capabilities
+off en masse with compiler directives that define
+PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
+or all four,
+along with directives to turn on any of the capabilities that you do
+want. The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the extra
+transformations but still leave the library fully capable of reading
+and writing PNG files with all known public chunks. Use of the
+PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library
+that is incapable of reading or writing ancillary chunks. If you are
+not using the progressive reading capability, you can turn that off
+with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING
+capability, which you'll still have).
+
+All the reading and writing specific code are in separate files, so the
+linker should only grab the files it needs. However, if you want to
+make sure, or if you are building a stand alone library, all the
+reading files start with pngr and all the writing files start with
+pngw. The files that don't match either (like png.c, pngtrans.c, etc.)
+are used for both reading and writing, and always need to be included.
+The progressive reader is in pngpread.c
+
+If you are creating or distributing a dynamically linked library (a .so
+or DLL file), you should not remove or disable any parts of the library,
+as this will cause applications linked with different versions of the
+library to fail if they call functions not available in your library.
+The size of the library itself should not be an issue, because only
+those sections that are actually used will be loaded into memory.
+
+Requesting debug printout
+
+The macro definition PNG_DEBUG can be used to request debugging
+printout. Set it to an integer value in the range 0 to 3. Higher
+numbers result in increasing amounts of debugging information. The
+information is printed to the "stderr" file, unless another file
+name is specified in the PNG_DEBUG_FILE macro definition.
+
+When PNG_DEBUG > 0, the following functions (macros) become available:
+
+ png_debug(level, message)
+ png_debug1(level, message, p1)
+ png_debug2(level, message, p1, p2)
+
+in which "level" is compared to PNG_DEBUG to decide whether to print
+the message, "message" is the formatted string to be printed,
+and p1 and p2 are parameters that are to be embedded in the string
+according to printf-style formatting directives. For example,
+
+ png_debug1(2, "foo=%d\n", foo);
+
+is expanded to
+
+ if(PNG_DEBUG > 2)
+ fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo);
+
+When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
+can still use PNG_DEBUG to control your own debugging:
+
+ #ifdef PNG_DEBUG
+ fprintf(stderr, ...
+ #endif
+
+When PNG_DEBUG = 1, the macros are defined, but only png_debug statements
+having level = 0 will be printed. There aren't any such statements in
+this version of libpng, but if you insert some they will be printed.
+
+VI. MNG support
+
+The MNG specification (available at http://www.libpng.org/pub/mng) allows
+certain extensions to PNG for PNG images that are embedded in MNG datastreams.
+Libpng can support some of these extensions. To enable them, use the
+png_permit_mng_features() function:
+
+ feature_set = png_permit_mng_features(png_ptr, mask)
+ mask is a png_uint_32 containing the bitwise OR of the
+ features you want to enable. These include
+ PNG_FLAG_MNG_EMPTY_PLTE
+ PNG_FLAG_MNG_FILTER_64
+ PNG_ALL_MNG_FEATURES
+ feature_set is a png_uint_32 that is the bitwise AND of
+ your mask with the set of MNG features that is
+ supported by the version of libpng that you are using.
+
+It is an error to use this function when reading or writing a standalone
+PNG file with the PNG 8-byte signature. The PNG datastream must be wrapped
+in a MNG datastream. As a minimum, it must have the MNG 8-byte signature
+and the MHDR and MEND chunks. Libpng does not provide support for these
+or any other MNG chunks; your application must provide its own support for
+them. You may wish to consider using libmng (available at
+http://www.libmng.com) instead.
+
+VII. Changes to Libpng from version 0.88
+
+It should be noted that versions of libpng later than 0.96 are not
+distributed by the original libpng author, Guy Schalnat, nor by
+Andreas Dilger, who had taken over from Guy during 1996 and 1997, and
+distributed versions 0.89 through 0.96, but rather by another member
+of the original PNG Group, Glenn Randers-Pehrson. Guy and Andreas are
+still alive and well, but they have moved on to other things.
+
+The old libpng functions png_read_init(), png_write_init(),
+png_info_init(), png_read_destroy(), and png_write_destroy() have been
+moved to PNG_INTERNAL in version 0.95 to discourage their use. These
+functions will be removed from libpng version 2.0.0.
+
+The preferred method of creating and initializing the libpng structures is
+via the png_create_read_struct(), png_create_write_struct(), and
+png_create_info_struct() because they isolate the size of the structures
+from the application, allow version error checking, and also allow the
+use of custom error handling routines during the initialization, which
+the old functions do not. The functions png_read_destroy() and
+png_write_destroy() do not actually free the memory that libpng
+allocated for these structs, but just reset the data structures, so they
+can be used instead of png_destroy_read_struct() and
+png_destroy_write_struct() if you feel there is too much system overhead
+allocating and freeing the png_struct for each image read.
+
+Setting the error callbacks via png_set_message_fn() before
+png_read_init() as was suggested in libpng-0.88 is no longer supported
+because this caused applications that do not use custom error functions
+to fail if the png_ptr was not initialized to zero. It is still possible
+to set the error callbacks AFTER png_read_init(), or to change them with
+png_set_error_fn(), which is essentially the same function, but with a new
+name to force compilation errors with applications that try to use the old
+method.
+
+Starting with version 1.0.7, you can find out which version of the library
+you are using at run-time:
+
+ png_uint_32 libpng_vn = png_access_version_number();
+
+The number libpng_vn is constructed from the major version, minor
+version with leading zero, and release number with leading zero,
+(e.g., libpng_vn for version 1.0.7 is 10007).
+
+You can also check which version of png.h you used when compiling your
+application:
+
+ png_uint_32 application_vn = PNG_LIBPNG_VER;
+
+VIII. Changes to Libpng from version 1.0.x to 1.2.x
+
+Support for user memory management was enabled by default. To
+accomplish this, the functions png_create_read_struct_2(),
+png_create_write_struct_2(), png_set_mem_fn(), png_get_mem_ptr(),
+png_malloc_default(), and png_free_default() were added.
+
+Support for the iTXt chunk has been enabled by default as of
+version 1.2.41.
+
+Support for certain MNG features was enabled.
+
+Support for numbered error messages was added. However, we never got
+around to actually numbering the error messages. The function
+png_set_strip_error_numbers() was added (Note: the prototype for this
+function was inadvertently removed from png.h in PNG_NO_ASSEMBLER_CODE
+builds of libpng-1.2.15. It was restored in libpng-1.2.36).
+
+The png_malloc_warn() function was added at libpng-1.2.3. This issues
+a png_warning and returns NULL instead of aborting when it fails to
+acquire the requested memory allocation.
+
+Support for setting user limits on image width and height was enabled
+by default. The functions png_set_user_limits(), png_get_user_width_max(),
+and png_get_user_height_max() were added at libpng-1.2.6.
+
+The png_set_add_alpha() function was added at libpng-1.2.7.
+
+The function png_set_expand_gray_1_2_4_to_8() was added at libpng-1.2.9.
+Unlike png_set_gray_1_2_4_to_8(), the new function does not expand the
+tRNS chunk to alpha. The png_set_gray_1_2_4_to_8() function is
+deprecated.
+
+A number of macro definitions in support of runtime selection of
+assembler code features (especially Intel MMX code support) were
+added at libpng-1.2.0:
+
+ PNG_ASM_FLAG_MMX_SUPPORT_COMPILED
+ PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
+ PNG_ASM_FLAG_MMX_READ_COMBINE_ROW
+ PNG_ASM_FLAG_MMX_READ_INTERLACE
+ PNG_ASM_FLAG_MMX_READ_FILTER_SUB
+ PNG_ASM_FLAG_MMX_READ_FILTER_UP
+ PNG_ASM_FLAG_MMX_READ_FILTER_AVG
+ PNG_ASM_FLAG_MMX_READ_FILTER_PAETH
+ PNG_ASM_FLAGS_INITIALIZED
+ PNG_MMX_READ_FLAGS
+ PNG_MMX_FLAGS
+ PNG_MMX_WRITE_FLAGS
+ PNG_MMX_FLAGS
+
+We added the following functions in support of runtime
+selection of assembler code features:
+
+ png_get_mmx_flagmask()
+ png_set_mmx_thresholds()
+ png_get_asm_flags()
+ png_get_mmx_bitdepth_threshold()
+ png_get_mmx_rowbytes_threshold()
+ png_set_asm_flags()
+
+We replaced all of these functions with simple stubs in libpng-1.2.20,
+when the Intel assembler code was removed due to a licensing issue.
+
+These macros are deprecated:
+
+ PNG_READ_TRANSFORMS_NOT_SUPPORTED
+ PNG_PROGRESSIVE_READ_NOT_SUPPORTED
+ PNG_NO_SEQUENTIAL_READ_SUPPORTED
+ PNG_WRITE_TRANSFORMS_NOT_SUPPORTED
+ PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED
+ PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED
+
+They have been replaced, respectively, by:
+
+ PNG_NO_READ_TRANSFORMS
+ PNG_NO_PROGRESSIVE_READ
+ PNG_NO_SEQUENTIAL_READ
+ PNG_NO_WRITE_TRANSFORMS
+ PNG_NO_READ_ANCILLARY_CHUNKS
+ PNG_NO_WRITE_ANCILLARY_CHUNKS
+
+PNG_MAX_UINT was replaced with PNG_UINT_31_MAX. It has been
+deprecated since libpng-1.0.16 and libpng-1.2.6.
+
+The function
+ png_check_sig(sig, num)
+was replaced with
+ !png_sig_cmp(sig, 0, num)
+It has been deprecated since libpng-0.90.
+
+The function
+ png_set_gray_1_2_4_to_8()
+which also expands tRNS to alpha was replaced with
+ png_set_expand_gray_1_2_4_to_8()
+which does not. It has been deprecated since libpng-1.0.18 and 1.2.9.
+
+IX. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
+
+Private libpng prototypes and macro definitions were moved from
+png.h and pngconf.h into a new pngpriv.h header file.
+
+Functions png_set_benign_errors(), png_benign_error(), and
+png_chunk_benign_error() were added.
+
+Support for setting the maximum amount of memory that the application
+will allocate for reading chunks was added, as a security measure.
+The functions png_set_chunk_cache_max() and png_get_chunk_cache_max()
+were added to the library.
+
+We implemented support for I/O states by adding png_ptr member io_state
+and functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
+
+We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level
+input transforms.
+
+Checking for and reporting of errors in the IHDR chunk is more thorough.
+
+Support for global arrays was removed, to improve thread safety.
+
+Some obsolete/deprecated macros and functions have been removed.
+
+Typecasted NULL definitions such as
+ #define png_voidp_NULL (png_voidp)NULL
+were eliminated. If you used these in your application, just use
+NULL instead.
+
+The png_struct and info_struct members "trans" and "trans_values" were
+changed to "trans_alpha" and "trans_color", respectively.
+
+The obsolete, unused pnggccrd.c and pngvcrd.c files and related makefiles
+were removed.
+
+The PNG_1_0_X and PNG_1_2_X macros were eliminated.
+
+The PNG_LEGACY_SUPPORTED macro was eliminated.
+
+Many WIN32_WCE #ifdefs were removed.
+
+The functions png_read_init(info_ptr), png_write_init(info_ptr),
+png_info_init(info_ptr), png_read_destroy(), and png_write_destroy()
+have been removed. They have been deprecated since libpng-0.95.
+
+The png_permit_empty_plte() was removed. It has been deprecated
+since libpng-1.0.9. Use png_permit_mng_features() instead.
+
+We removed the obsolete stub functions png_get_mmx_flagmask(),
+png_set_mmx_thresholds(), png_get_asm_flags(),
+png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(),
+png_set_asm_flags(), and png_mmx_supported()
+
+We removed the obsolete png_check_sig(), png_memcpy_check(), and
+png_memset_check() functions. Instead use !png_sig_cmp(), png_memcpy(),
+and png_memset(), respectively.
+
+The function png_set_gray_1_2_4_to_8() was removed. It has been
+deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with
+png_set_expand_gray_1_2_4_to_8() because the former function also
+expanded palette images.
+
+We changed the prototype for png_malloc() from
+ png_malloc(png_structp png_ptr, png_uint_32 size)
+to
+ png_malloc(png_structp png_ptr, png_alloc_size_t size)
+
+This also applies to the prototype for the user replacement malloc_fn().
+
+The png_calloc() function was added and is used in place of
+of "png_malloc(); png_memset();" except in the case in png_read_png()
+where the array consists of pointers; in this case a "for" loop is used
+after the png_malloc() to set the pointers to NULL, to give robust.
+behavior in case the application runs out of memory part-way through
+the process.
+
+We changed the prototypes of png_get_compression_buffer_size() and
+png_set_compression_buffer_size() to work with png_size_t instead of
+png_uint_32.
+
+Support for numbered error messages was removed by default, since we
+never got around to actually numbering the error messages. The function
+png_set_strip_error_numbers() was removed from the library by default.
+
+The png_zalloc() and png_zfree() functions are no longer exported.
+The png_zalloc() function no longer zeroes out the memory that it
+allocates.
+
+Support for dithering was disabled by default in libpng-1.4.0, because
+been well tested and doesn't actually "dither". The code was not
+removed, however, and could be enabled by building libpng with
+PNG_READ_DITHER_SUPPORTED defined. In libpng-1.4.2, this support
+was reenabled, but the function was renamed png_set_quantize() to
+reflect more accurately what it actually does. At the same time,
+the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros were also renamed to
+PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS.
+
+We removed the trailing '.' from the warning and error messages.
+
+X. Detecting libpng
+
+The png_get_io_ptr() function has been present since libpng-0.88, has never
+changed, and is unaffected by conditional compilation macros. It is the
+best choice for use in configure scripts for detecting the presence of any
+libpng version since 0.88. In an autoconf "configure.in" you could use
+
+ AC_CHECK_LIB(png, png_get_io_ptr, ...
+
+XI. Source code repository
+
+Since about February 2009, version 1.2.34, libpng has been under "git" source
+control. The git repository was built from old libpng-x.y.z.tar.gz files
+going back to version 0.70. You can access the git repository (read only)
+at
+
+ git://libpng.git.sourceforge.net/gitroot/libpng
+
+or you can browse it via "gitweb" at
+
+ http://libpng.git.sourceforge.net/git/gitweb.cgi?p=libpng
+
+Patches can be sent to glennrp at users.sourceforge.net or to
+png-mng-implement at lists.sourceforge.net or you can upload them to
+the libpng bug tracker at
+
+ http://libpng.sourceforge.net
+
+XII. Coding style
+
+Our coding style is similar to the "Allman" style, with curly
+braces on separate lines:
+
+ if (condition)
+ {
+ action;
+ }
+
+ else if (another condition)
+ {
+ another action;
+ }
+
+The braces can be omitted from simple one-line actions:
+
+ if (condition)
+ return (0);
+
+We use 3-space indentation, except for continued statements which
+are usually indented the same as the first line of the statement
+plus four more spaces.
+
+For macro definitions we use 2-space indentation, always leaving the "#"
+in the first column.
+
+ #ifndef PNG_NO_FEATURE
+ # ifndef PNG_FEATURE_SUPPORTED
+ # define PNG_FEATURE_SUPPORTED
+ # endif
+ #endif
+
+Comments appear with the leading "/*" at the same indentation as
+the statement that follows the comment:
+
+ /* Single-line comment */
+ statement;
+
+ /* This is a multiple-line
+ * comment.
+ */
+ statement;
+
+Very short comments can be placed after the end of the statement
+to which they pertain:
+
+ statement; /* comment */
+
+We don't use C++ style ("//") comments. We have, however,
+used them in the past in some now-abandoned MMX assembler
+code.
+
+Functions and their curly braces are not indented, and
+exported functions are marked with PNGAPI:
+
+ /* This is a public function that is visible to
+ * application programers. It does thus-and-so.
+ */
+ void PNGAPI
+ png_exported_function(png_ptr, png_info, foo)
+ {
+ body;
+ }
+
+The prototypes for all exported functions appear in png.h,
+above the comment that says
+
+ /* Maintainer: Put new public prototypes here ... */
+
+We mark all non-exported functions with "/* PRIVATE */"":
+
+ void /* PRIVATE */
+ png_non_exported_function(png_ptr, png_info, foo)
+ {
+ body;
+ }
+
+The prototypes for non-exported functions (except for those in
+pngtest) appear in
+pngpriv.h
+above the comment that says
+
+ /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
+
+The names of all exported functions and variables begin
+with "png_", and all publicly visible C preprocessor
+macros begin with "PNG_".
+
+We put a space after each comma and after each semicolon
+in "for" statments, and we put spaces before and after each
+C binary operator and after "for" or "while", and before
+"?". We don't put a space between a typecast and the expression
+being cast, nor do we put one between a function name and the
+left parenthesis that follows it:
+
+ for (i = 2; i > 0; --i)
+ y[i] = a(x) + (int)b;
+
+We prefer #ifdef and #ifndef to #if defined() and if !defined()
+when there is only one macro being tested.
+
+We do not use the TAB character for indentation in the C sources.
+
+Lines do not exceed 80 characters.
+
+Other rules can be inferred by inspecting the libpng source.
+
+XIII. Y2K Compliance in libpng
+
+September 23, 2010
+
+Since the PNG Development group is an ad-hoc body, we can't make
+an official declaration.
+
+This is your unofficial assurance that libpng from version 0.71 and
+upward through 1.4.4 are Y2K compliant. It is my belief that earlier
+versions were also Y2K compliant.
+
+Libpng only has three year fields. One is a 2-byte unsigned integer that
+will hold years up to 65535. The other two hold the date in text
+format, and will hold years up to 9999.
+
+The integer is
+ "png_uint_16 year" in png_time_struct.
+
+The strings are
+ "png_charp time_buffer" in png_struct and
+ "near_time_buffer", which is a local character string in png.c.
+
+There are seven time-related functions:
+
+ png_convert_to_rfc_1123() in png.c
+ (formerly png_convert_to_rfc_1152() in error)
+ png_convert_from_struct_tm() in pngwrite.c, called
+ in pngwrite.c
+ png_convert_from_time_t() in pngwrite.c
+ png_get_tIME() in pngget.c
+ png_handle_tIME() in pngrutil.c, called in pngread.c
+ png_set_tIME() in pngset.c
+ png_write_tIME() in pngwutil.c, called in pngwrite.c
+
+All appear to handle dates properly in a Y2K environment. The
+png_convert_from_time_t() function calls gmtime() to convert from system
+clock time, which returns (year - 1900), which we properly convert to
+the full 4-digit year. There is a possibility that applications using
+libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+function, or that they are incorrectly passing only a 2-digit year
+instead of "year - 1900" into the png_convert_from_struct_tm() function,
+but this is not under our control. The libpng documentation has always
+stated that it works with 4-digit years, and the APIs have been
+documented as such.
+
+The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
+integer to hold the year, and can hold years as large as 65535.
+
+zlib, upon which libpng depends, is also Y2K compliant. It contains
+no date-related code.
+
+
+ Glenn Randers-Pehrson
+ libpng maintainer
+ PNG Development Group
--- /dev/null
+
+/* png.c - location for general purpose libpng functions
+ *
+ * Last changed in libpng 1.4.2 [May 6, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#define PNG_NO_EXTERN
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#include "pngpriv.h"
+
+/* Generate a compiler error if there is an old png.h in the search path. */
+typedef version_1_4_4 Your_png_h_is_not_version_1_4_4;
+
+/* Version information for C files. This had better match the version
+ * string defined in png.h.
+ */
+
+/* Tells libpng that we have already handled the first "num_bytes" bytes
+ * of the PNG file signature. If the PNG data is embedded into another
+ * stream we can set num_bytes = 8 so that libpng will not attempt to read
+ * or write any of the magic bytes before it starts on the IHDR.
+ */
+
+#ifdef PNG_READ_SUPPORTED
+void PNGAPI
+png_set_sig_bytes(png_structp png_ptr, int num_bytes)
+{
+ png_debug(1, "in png_set_sig_bytes");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (num_bytes > 8)
+ png_error(png_ptr, "Too many bytes for PNG signature");
+
+ png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
+}
+
+/* Checks whether the supplied bytes match the PNG signature. We allow
+ * checking less than the full 8-byte signature so that those apps that
+ * already read the first few bytes of a file to determine the file type
+ * can simply check the remaining bytes for extra assurance. Returns
+ * an integer less than, equal to, or greater than zero if sig is found,
+ * respectively, to be less than, to match, or be greater than the correct
+ * PNG signature (this is the same behaviour as strcmp, memcmp, etc).
+ */
+int PNGAPI
+png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
+{
+ png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+ if (num_to_check > 8)
+ num_to_check = 8;
+ else if (num_to_check < 1)
+ return (-1);
+
+ if (start > 7)
+ return (-1);
+
+ if (start + num_to_check > 8)
+ num_to_check = 8 - start;
+
+ return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
+}
+
+#endif /* PNG_READ_SUPPORTED */
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Function to allocate memory for zlib and clear it to 0. */
+voidpf /* PRIVATE */
+png_zalloc(voidpf png_ptr, uInt items, uInt size)
+{
+ png_voidp ptr;
+ png_structp p=(png_structp)png_ptr;
+ png_uint_32 save_flags=p->flags;
+ png_alloc_size_t num_bytes;
+
+ if (png_ptr == NULL)
+ return (NULL);
+ if (items > PNG_UINT_32_MAX/size)
+ {
+ png_warning (p, "Potential overflow in png_zalloc()");
+ return (NULL);
+ }
+ num_bytes = (png_alloc_size_t)items * size;
+
+ p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
+ ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
+ p->flags=save_flags;
+
+ return ((voidpf)ptr);
+}
+
+/* Function to free memory for zlib */
+void /* PRIVATE */
+png_zfree(voidpf png_ptr, voidpf ptr)
+{
+ png_free((png_structp)png_ptr, (png_voidp)ptr);
+}
+
+/* Reset the CRC variable to 32 bits of 1's. Care must be taken
+ * in case CRC is > 32 bits to leave the top bits 0.
+ */
+void /* PRIVATE */
+png_reset_crc(png_structp png_ptr)
+{
+ png_ptr->crc = crc32(0, Z_NULL, 0);
+}
+
+/* Calculate the CRC over a section of data. We can only pass as
+ * much data to this routine as the largest single buffer size. We
+ * also check that this data will actually be used before going to the
+ * trouble of calculating it.
+ */
+void /* PRIVATE */
+png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
+{
+ int need_crc = 1;
+
+ if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+ (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+ need_crc = 0;
+ }
+ else /* critical */
+ {
+ if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
+ need_crc = 0;
+ }
+
+ if (need_crc)
+ png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length);
+}
+
+/* Allocate the memory for an info_struct for the application. We don't
+ * really need the png_ptr, but it could potentially be useful in the
+ * future. This should be used in favour of malloc(png_sizeof(png_info))
+ * and png_info_init() so that applications that want to use a shared
+ * libpng don't have to be recompiled if png_info changes size.
+ */
+png_infop PNGAPI
+png_create_info_struct(png_structp png_ptr)
+{
+ png_infop info_ptr;
+
+ png_debug(1, "in png_create_info_struct");
+
+ if (png_ptr == NULL)
+ return (NULL);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
+ png_ptr->malloc_fn, png_ptr->mem_ptr);
+#else
+ info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
+#endif
+ if (info_ptr != NULL)
+ png_info_init_3(&info_ptr, png_sizeof(png_info));
+
+ return (info_ptr);
+}
+
+/* This function frees the memory associated with a single info struct.
+ * Normally, one would use either png_destroy_read_struct() or
+ * png_destroy_write_struct() to free an info struct, but this may be
+ * useful for some applications.
+ */
+void PNGAPI
+png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
+{
+ png_infop info_ptr = NULL;
+
+ png_debug(1, "in png_destroy_info_struct");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (info_ptr_ptr != NULL)
+ info_ptr = *info_ptr_ptr;
+
+ if (info_ptr != NULL)
+ {
+ png_info_destroy(png_ptr, info_ptr);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
+ png_ptr->mem_ptr);
+#else
+ png_destroy_struct((png_voidp)info_ptr);
+#endif
+ *info_ptr_ptr = NULL;
+ }
+}
+
+/* Initialize the info structure. This is now an internal function (0.89)
+ * and applications using it are urged to use png_create_info_struct()
+ * instead.
+ */
+
+void PNGAPI
+png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
+{
+ png_infop info_ptr = *ptr_ptr;
+
+ png_debug(1, "in png_info_init_3");
+
+ if (info_ptr == NULL)
+ return;
+
+ if (png_sizeof(png_info) > png_info_struct_size)
+ {
+ png_destroy_struct(info_ptr);
+ info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
+ *ptr_ptr = info_ptr;
+ }
+
+ /* Set everything to 0 */
+ png_memset(info_ptr, 0, png_sizeof(png_info));
+}
+
+void PNGAPI
+png_data_freer(png_structp png_ptr, png_infop info_ptr,
+ int freer, png_uint_32 mask)
+{
+ png_debug(1, "in png_data_freer");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (freer == PNG_DESTROY_WILL_FREE_DATA)
+ info_ptr->free_me |= mask;
+ else if (freer == PNG_USER_WILL_FREE_DATA)
+ info_ptr->free_me &= ~mask;
+ else
+ png_warning(png_ptr,
+ "Unknown freer parameter in png_data_freer");
+}
+
+void PNGAPI
+png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
+ int num)
+{
+ png_debug(1, "in png_free_data");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+#ifdef PNG_TEXT_SUPPORTED
+ /* Free text item num or (if num == -1) all text items */
+ if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
+ {
+ if (num != -1)
+ {
+ if (info_ptr->text && info_ptr->text[num].key)
+ {
+ png_free(png_ptr, info_ptr->text[num].key);
+ info_ptr->text[num].key = NULL;
+ }
+ }
+ else
+ {
+ int i;
+ for (i = 0; i < info_ptr->num_text; i++)
+ png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
+ png_free(png_ptr, info_ptr->text);
+ info_ptr->text = NULL;
+ info_ptr->num_text=0;
+ }
+ }
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+ /* Free any tRNS entry */
+ if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
+ {
+ png_free(png_ptr, info_ptr->trans_alpha);
+ info_ptr->trans_alpha = NULL;
+ info_ptr->valid &= ~PNG_INFO_tRNS;
+ }
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+ /* Free any sCAL entry */
+ if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
+ {
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+ png_free(png_ptr, info_ptr->scal_s_width);
+ png_free(png_ptr, info_ptr->scal_s_height);
+ info_ptr->scal_s_width = NULL;
+ info_ptr->scal_s_height = NULL;
+#endif
+ info_ptr->valid &= ~PNG_INFO_sCAL;
+ }
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+ /* Free any pCAL entry */
+ if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
+ {
+ png_free(png_ptr, info_ptr->pcal_purpose);
+ png_free(png_ptr, info_ptr->pcal_units);
+ info_ptr->pcal_purpose = NULL;
+ info_ptr->pcal_units = NULL;
+ if (info_ptr->pcal_params != NULL)
+ {
+ int i;
+ for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
+ {
+ png_free(png_ptr, info_ptr->pcal_params[i]);
+ info_ptr->pcal_params[i] = NULL;
+ }
+ png_free(png_ptr, info_ptr->pcal_params);
+ info_ptr->pcal_params = NULL;
+ }
+ info_ptr->valid &= ~PNG_INFO_pCAL;
+ }
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+ /* Free any iCCP entry */
+ if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
+ {
+ png_free(png_ptr, info_ptr->iccp_name);
+ png_free(png_ptr, info_ptr->iccp_profile);
+ info_ptr->iccp_name = NULL;
+ info_ptr->iccp_profile = NULL;
+ info_ptr->valid &= ~PNG_INFO_iCCP;
+ }
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+ /* Free a given sPLT entry, or (if num == -1) all sPLT entries */
+ if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
+ {
+ if (num != -1)
+ {
+ if (info_ptr->splt_palettes)
+ {
+ png_free(png_ptr, info_ptr->splt_palettes[num].name);
+ png_free(png_ptr, info_ptr->splt_palettes[num].entries);
+ info_ptr->splt_palettes[num].name = NULL;
+ info_ptr->splt_palettes[num].entries = NULL;
+ }
+ }
+ else
+ {
+ if (info_ptr->splt_palettes_num)
+ {
+ int i;
+ for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+ png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
+
+ png_free(png_ptr, info_ptr->splt_palettes);
+ info_ptr->splt_palettes = NULL;
+ info_ptr->splt_palettes_num = 0;
+ }
+ info_ptr->valid &= ~PNG_INFO_sPLT;
+ }
+ }
+#endif
+
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+ if (png_ptr->unknown_chunk.data)
+ {
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+ }
+
+ if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
+ {
+ if (num != -1)
+ {
+ if (info_ptr->unknown_chunks)
+ {
+ png_free(png_ptr, info_ptr->unknown_chunks[num].data);
+ info_ptr->unknown_chunks[num].data = NULL;
+ }
+ }
+ else
+ {
+ int i;
+
+ if (info_ptr->unknown_chunks_num)
+ {
+ for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
+ png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
+
+ png_free(png_ptr, info_ptr->unknown_chunks);
+ info_ptr->unknown_chunks = NULL;
+ info_ptr->unknown_chunks_num = 0;
+ }
+ }
+ }
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+ /* Free any hIST entry */
+ if ((mask & PNG_FREE_HIST) & info_ptr->free_me)
+ {
+ png_free(png_ptr, info_ptr->hist);
+ info_ptr->hist = NULL;
+ info_ptr->valid &= ~PNG_INFO_hIST;
+ }
+#endif
+
+ /* Free any PLTE entry that was internally allocated */
+ if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
+ {
+ png_zfree(png_ptr, info_ptr->palette);
+ info_ptr->palette = NULL;
+ info_ptr->valid &= ~PNG_INFO_PLTE;
+ info_ptr->num_palette = 0;
+ }
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+ /* Free any image bits attached to the info structure */
+ if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
+ {
+ if (info_ptr->row_pointers)
+ {
+ int row;
+ for (row = 0; row < (int)info_ptr->height; row++)
+ {
+ png_free(png_ptr, info_ptr->row_pointers[row]);
+ info_ptr->row_pointers[row] = NULL;
+ }
+ png_free(png_ptr, info_ptr->row_pointers);
+ info_ptr->row_pointers = NULL;
+ }
+ info_ptr->valid &= ~PNG_INFO_IDAT;
+ }
+#endif
+
+ if (num == -1)
+ info_ptr->free_me &= ~mask;
+ else
+ info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
+}
+
+/* This is an internal routine to free any memory that the info struct is
+ * pointing to before re-using it or freeing the struct itself. Recall
+ * that png_free() checks for NULL pointers for us.
+ */
+void /* PRIVATE */
+png_info_destroy(png_structp png_ptr, png_infop info_ptr)
+{
+ png_debug(1, "in png_info_destroy");
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ if (png_ptr->num_chunk_list)
+ {
+ png_free(png_ptr, png_ptr->chunk_list);
+ png_ptr->chunk_list = NULL;
+ png_ptr->num_chunk_list = 0;
+ }
+#endif
+
+ png_info_init_3(&info_ptr, png_sizeof(png_info));
+}
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
+
+/* This function returns a pointer to the io_ptr associated with the user
+ * functions. The application should free any memory associated with this
+ * pointer before png_write_destroy() or png_read_destroy() are called.
+ */
+png_voidp PNGAPI
+png_get_io_ptr(png_structp png_ptr)
+{
+ if (png_ptr == NULL)
+ return (NULL);
+ return (png_ptr->io_ptr);
+}
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#ifdef PNG_STDIO_SUPPORTED
+/* Initialize the default input/output functions for the PNG file. If you
+ * use your own read or write routines, you can call either png_set_read_fn()
+ * or png_set_write_fn() instead of png_init_io(). If you have defined
+ * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
+ * necessarily available.
+ */
+void PNGAPI
+png_init_io(png_structp png_ptr, png_FILE_p fp)
+{
+ png_debug(1, "in png_init_io");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->io_ptr = (png_voidp)fp;
+}
+#endif
+
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+/* Convert the supplied time into an RFC 1123 string suitable for use in
+ * a "Creation Time" or other text-based time string.
+ */
+png_charp PNGAPI
+png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
+{
+ static PNG_CONST char short_months[12][4] =
+ {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+ "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
+
+ if (png_ptr == NULL)
+ return (NULL);
+ if (png_ptr->time_buffer == NULL)
+ {
+ png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
+ png_sizeof(char)));
+ }
+
+#ifdef USE_FAR_KEYWORD
+ {
+ char near_time_buf[29];
+ png_snprintf6(near_time_buf, 29, "%d %s %d %02d:%02d:%02d +0000",
+ ptime->day % 32, short_months[(ptime->month - 1) % 12],
+ ptime->year, ptime->hour % 24, ptime->minute % 60,
+ ptime->second % 61);
+ png_memcpy(png_ptr->time_buffer, near_time_buf,
+ 29*png_sizeof(char));
+ }
+#else
+ png_snprintf6(png_ptr->time_buffer, 29, "%d %s %d %02d:%02d:%02d +0000",
+ ptime->day % 32, short_months[(ptime->month - 1) % 12],
+ ptime->year, ptime->hour % 24, ptime->minute % 60,
+ ptime->second % 61);
+#endif
+ return ((png_charp)png_ptr->time_buffer);
+}
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
+
+png_charp PNGAPI
+png_get_copyright(png_structp png_ptr)
+{
+ png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
+#ifdef PNG_STRING_COPYRIGHT
+ return PNG_STRING_COPYRIGHT
+#else
+#ifdef __STDC__
+ return ((png_charp) PNG_STRING_NEWLINE \
+ "libpng version 1.4.4 - September 23, 2010" PNG_STRING_NEWLINE \
+ "Copyright (c) 1998-2010 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
+ "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
+ "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
+ PNG_STRING_NEWLINE);
+#else
+ return ((png_charp) "libpng version 1.4.4 - September 23, 2010\
+ Copyright (c) 1998-2010 Glenn Randers-Pehrson\
+ Copyright (c) 1996-1997 Andreas Dilger\
+ Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.");
+#endif
+#endif
+}
+
+/* The following return the library version as a short string in the
+ * format 1.0.0 through 99.99.99zz. To get the version of *.h files
+ * used with your application, print out PNG_LIBPNG_VER_STRING, which
+ * is defined in png.h.
+ * Note: now there is no difference between png_get_libpng_ver() and
+ * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
+ * it is guaranteed that png.c uses the correct version of png.h.
+ */
+png_charp PNGAPI
+png_get_libpng_ver(png_structp png_ptr)
+{
+ /* Version of *.c files used when building libpng */
+ png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
+ return ((png_charp) PNG_LIBPNG_VER_STRING);
+}
+
+png_charp PNGAPI
+png_get_header_ver(png_structp png_ptr)
+{
+ /* Version of *.h files used when building libpng */
+ png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
+ return ((png_charp) PNG_LIBPNG_VER_STRING);
+}
+
+png_charp PNGAPI
+png_get_header_version(png_structp png_ptr)
+{
+ /* Returns longer string containing both version and date */
+ png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
+#ifdef __STDC__
+ return ((png_charp) PNG_HEADER_VERSION_STRING
+#ifndef PNG_READ_SUPPORTED
+ " (NO READ SUPPORT)"
+#endif
+ PNG_STRING_NEWLINE);
+#else
+ return ((png_charp) PNG_HEADER_VERSION_STRING);
+#endif
+}
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+int PNGAPI
+png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
+{
+ /* Check chunk_name and return "keep" value if it's on the list, else 0 */
+ int i;
+ png_bytep p;
+ if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0)
+ return 0;
+ p = png_ptr->chunk_list + png_ptr->num_chunk_list*5 - 5;
+ for (i = png_ptr->num_chunk_list; i; i--, p -= 5)
+ if (!png_memcmp(chunk_name, p, 4))
+ return ((int)*(p + 4));
+ return 0;
+}
+#endif
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
+
+#ifdef PNG_READ_SUPPORTED
+/* This function, added to libpng-1.0.6g, is untested. */
+int PNGAPI
+png_reset_zstream(png_structp png_ptr)
+{
+ if (png_ptr == NULL)
+ return Z_STREAM_ERROR;
+ return (inflateReset(&png_ptr->zstream));
+}
+#endif /* PNG_READ_SUPPORTED */
+
+/* This function was added to libpng-1.0.7 */
+png_uint_32 PNGAPI
+png_access_version_number(void)
+{
+ /* Version of *.c files used when building libpng */
+ return((png_uint_32) PNG_LIBPNG_VER);
+}
+
+
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#ifdef PNG_SIZE_T
+/* Added at libpng version 1.2.6 */
+ PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
+png_size_t PNGAPI
+png_convert_size(size_t size)
+{
+ if (size > (png_size_t)-1)
+ PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */
+ return ((png_size_t)size);
+}
+#endif /* PNG_SIZE_T */
+
+/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */
+#ifdef PNG_cHRM_SUPPORTED
+#ifdef PNG_CHECK_cHRM_SUPPORTED
+
+/*
+ * Multiply two 32-bit numbers, V1 and V2, using 32-bit
+ * arithmetic, to produce a 64 bit result in the HI/LO words.
+ *
+ * A B
+ * x C D
+ * ------
+ * AD || BD
+ * AC || CB || 0
+ *
+ * where A and B are the high and low 16-bit words of V1,
+ * C and D are the 16-bit words of V2, AD is the product of
+ * A and D, and X || Y is (X << 16) + Y.
+*/
+
+void /* PRIVATE */
+png_64bit_product (long v1, long v2, unsigned long *hi_product,
+ unsigned long *lo_product)
+{
+ int a, b, c, d;
+ long lo, hi, x, y;
+
+ a = (v1 >> 16) & 0xffff;
+ b = v1 & 0xffff;
+ c = (v2 >> 16) & 0xffff;
+ d = v2 & 0xffff;
+
+ lo = b * d; /* BD */
+ x = a * d + c * b; /* AD + CB */
+ y = ((lo >> 16) & 0xffff) + x;
+
+ lo = (lo & 0xffff) | ((y & 0xffff) << 16);
+ hi = (y >> 16) & 0xffff;
+
+ hi += a * c; /* AC */
+
+ *hi_product = (unsigned long)hi;
+ *lo_product = (unsigned long)lo;
+}
+
+int /* PRIVATE */
+png_check_cHRM_fixed(png_structp png_ptr,
+ png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
+ png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
+ png_fixed_point blue_x, png_fixed_point blue_y)
+{
+ int ret = 1;
+ unsigned long xy_hi,xy_lo,yx_hi,yx_lo;
+
+ png_debug(1, "in function png_check_cHRM_fixed");
+
+ if (png_ptr == NULL)
+ return 0;
+
+ if (white_x < 0 || white_y <= 0 ||
+ red_x < 0 || red_y < 0 ||
+ green_x < 0 || green_y < 0 ||
+ blue_x < 0 || blue_y < 0)
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to set negative chromaticity value");
+ ret = 0;
+ }
+ if (white_x > (png_fixed_point) PNG_UINT_31_MAX ||
+ white_y > (png_fixed_point) PNG_UINT_31_MAX ||
+ red_x > (png_fixed_point) PNG_UINT_31_MAX ||
+ red_y > (png_fixed_point) PNG_UINT_31_MAX ||
+ green_x > (png_fixed_point) PNG_UINT_31_MAX ||
+ green_y > (png_fixed_point) PNG_UINT_31_MAX ||
+ blue_x > (png_fixed_point) PNG_UINT_31_MAX ||
+ blue_y > (png_fixed_point) PNG_UINT_31_MAX )
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to set chromaticity value exceeding 21474.83");
+ ret = 0;
+ }
+ if (white_x > 100000L - white_y)
+ {
+ png_warning(png_ptr, "Invalid cHRM white point");
+ ret = 0;
+ }
+ if (red_x > 100000L - red_y)
+ {
+ png_warning(png_ptr, "Invalid cHRM red point");
+ ret = 0;
+ }
+ if (green_x > 100000L - green_y)
+ {
+ png_warning(png_ptr, "Invalid cHRM green point");
+ ret = 0;
+ }
+ if (blue_x > 100000L - blue_y)
+ {
+ png_warning(png_ptr, "Invalid cHRM blue point");
+ ret = 0;
+ }
+
+ png_64bit_product(green_x - red_x, blue_y - red_y, &xy_hi, &xy_lo);
+ png_64bit_product(green_y - red_y, blue_x - red_x, &yx_hi, &yx_lo);
+
+ if (xy_hi == yx_hi && xy_lo == yx_lo)
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to set cHRM RGB triangle with zero area");
+ ret = 0;
+ }
+
+ return ret;
+}
+#endif /* PNG_CHECK_cHRM_SUPPORTED */
+#endif /* PNG_cHRM_SUPPORTED */
+
+void /* PRIVATE */
+png_check_IHDR(png_structp png_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_type, int compression_type,
+ int filter_type)
+{
+ int error = 0;
+
+ /* Check for width and height valid values */
+ if (width == 0)
+ {
+ png_warning(png_ptr, "Image width is zero in IHDR");
+ error = 1;
+ }
+
+ if (height == 0)
+ {
+ png_warning(png_ptr, "Image height is zero in IHDR");
+ error = 1;
+ }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ if (width > png_ptr->user_width_max || width > PNG_USER_WIDTH_MAX)
+#else
+ if (width > PNG_USER_WIDTH_MAX)
+#endif
+ {
+ png_warning(png_ptr, "Image width exceeds user limit in IHDR");
+ error = 1;
+ }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ if (height > png_ptr->user_height_max || height > PNG_USER_HEIGHT_MAX)
+#else
+ if (height > PNG_USER_HEIGHT_MAX)
+#endif
+ {
+ png_warning(png_ptr, "Image height exceeds user limit in IHDR");
+ error = 1;
+ }
+
+ if (width > PNG_UINT_31_MAX)
+ {
+ png_warning(png_ptr, "Invalid image width in IHDR");
+ error = 1;
+ }
+
+ if ( height > PNG_UINT_31_MAX)
+ {
+ png_warning(png_ptr, "Invalid image height in IHDR");
+ error = 1;
+ }
+
+ if ( width > (PNG_UINT_32_MAX
+ >> 3) /* 8-byte RGBA pixels */
+ - 64 /* bigrowbuf hack */
+ - 1 /* filter byte */
+ - 7*8 /* rounding of width to multiple of 8 pixels */
+ - 8) /* extra max_pixel_depth pad */
+ png_warning(png_ptr, "Width is too large for libpng to process pixels");
+
+ /* Check other values */
+ if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
+ bit_depth != 8 && bit_depth != 16)
+ {
+ png_warning(png_ptr, "Invalid bit depth in IHDR");
+ error = 1;
+ }
+
+ if (color_type < 0 || color_type == 1 ||
+ color_type == 5 || color_type > 6)
+ {
+ png_warning(png_ptr, "Invalid color type in IHDR");
+ error = 1;
+ }
+
+ if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
+ ((color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
+ {
+ png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR");
+ error = 1;
+ }
+
+ if (interlace_type >= PNG_INTERLACE_LAST)
+ {
+ png_warning(png_ptr, "Unknown interlace method in IHDR");
+ error = 1;
+ }
+
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Unknown compression method in IHDR");
+ error = 1;
+ }
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ /* Accept filter_method 64 (intrapixel differencing) only if
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+ * 2. Libpng did not read a PNG signature (this filter_method is only
+ * used in PNG datastreams that are embedded in MNG datastreams) and
+ * 3. The application called png_permit_mng_features with a mask that
+ * included PNG_FLAG_MNG_FILTER_64 and
+ * 4. The filter_method is 64 and
+ * 5. The color_type is RGB or RGBA
+ */
+ if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) &&
+ png_ptr->mng_features_permitted)
+ png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+
+ if (filter_type != PNG_FILTER_TYPE_BASE)
+ {
+ if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+ (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
+ ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
+ (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+ {
+ png_warning(png_ptr, "Unknown filter method in IHDR");
+ error = 1;
+ }
+
+ if (png_ptr->mode & PNG_HAVE_PNG_SIGNATURE)
+ {
+ png_warning(png_ptr, "Invalid filter method in IHDR");
+ error = 1;
+ }
+ }
+
+#else
+ if (filter_type != PNG_FILTER_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Unknown filter method in IHDR");
+ error = 1;
+ }
+#endif
+
+ if (error == 1)
+ png_error(png_ptr, "Invalid IHDR data");
+}
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
--- /dev/null
+
+/* png.h - header file for PNG reference library
+ *
+ * libpng version 1.4.4 - September 23, 2010
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license (See LICENSE, below)
+ *
+ * Authors and maintainers:
+ * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
+ * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
+ * libpng versions 0.97, January 1998, through 1.4.4 - September 23, 2010: Glenn
+ * See also "Contributing Authors", below.
+ *
+ * Note about libpng version numbers:
+ *
+ * Due to various miscommunications, unforeseen code incompatibilities
+ * and occasional factors outside the authors' control, version numbering
+ * on the library has not always been consistent and straightforward.
+ * The following table summarizes matters since version 0.89c, which was
+ * the first widely used release:
+ *
+ * source png.h png.h shared-lib
+ * version string int version
+ * ------- ------ ----- ----------
+ * 0.89c "1.0 beta 3" 0.89 89 1.0.89
+ * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
+ * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
+ * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
+ * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
+ * 0.97c 0.97 97 2.0.97
+ * 0.98 0.98 98 2.0.98
+ * 0.99 0.99 98 2.0.99
+ * 0.99a-m 0.99 99 2.0.99
+ * 1.00 1.00 100 2.1.0 [100 should be 10000]
+ * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
+ * 1.0.1 png.h string is 10001 2.1.0
+ * 1.0.1a-e identical to the 10002 from here on, the shared library
+ * 1.0.2 source version) 10002 is 2.V where V is the source code
+ * 1.0.2a-b 10003 version, except as noted.
+ * 1.0.3 10003
+ * 1.0.3a-d 10004
+ * 1.0.4 10004
+ * 1.0.4a-f 10005
+ * 1.0.5 (+ 2 patches) 10005
+ * 1.0.5a-d 10006
+ * 1.0.5e-r 10100 (not source compatible)
+ * 1.0.5s-v 10006 (not binary compatible)
+ * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
+ * 1.0.6d-f 10007 (still binary incompatible)
+ * 1.0.6g 10007
+ * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
+ * 1.0.6i 10007 10.6i
+ * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
+ * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
+ * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
+ * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
+ * 1.0.7 1 10007 (still compatible)
+ * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
+ * 1.0.8rc1 1 10008 2.1.0.8rc1
+ * 1.0.8 1 10008 2.1.0.8
+ * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
+ * 1.0.9rc1 1 10009 2.1.0.9rc1
+ * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
+ * 1.0.9rc2 1 10009 2.1.0.9rc2
+ * 1.0.9 1 10009 2.1.0.9
+ * 1.0.10beta1 1 10010 2.1.0.10beta1
+ * 1.0.10rc1 1 10010 2.1.0.10rc1
+ * 1.0.10 1 10010 2.1.0.10
+ * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
+ * 1.0.11rc1 1 10011 2.1.0.11rc1
+ * 1.0.11 1 10011 2.1.0.11
+ * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
+ * 1.0.12rc1 2 10012 2.1.0.12rc1
+ * 1.0.12 2 10012 2.1.0.12
+ * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
+ * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
+ * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5
+ * 1.2.0rc1 3 10200 3.1.2.0rc1
+ * 1.2.0 3 10200 3.1.2.0
+ * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4
+ * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2
+ * 1.2.1 3 10201 3.1.2.1
+ * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6
+ * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1
+ * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1
+ * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1
+ * 1.0.13 10 10013 10.so.0.1.0.13
+ * 1.2.2 12 10202 12.so.0.1.2.2
+ * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6
+ * 1.2.3 12 10203 12.so.0.1.2.3
+ * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3
+ * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1
+ * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1
+ * 1.0.14 10 10014 10.so.0.1.0.14
+ * 1.2.4 13 10204 12.so.0.1.2.4
+ * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2
+ * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3
+ * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3
+ * 1.0.15 10 10015 10.so.0.1.0.15
+ * 1.2.5 13 10205 12.so.0.1.2.5
+ * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4
+ * 1.0.16 10 10016 10.so.0.1.0.16
+ * 1.2.6 13 10206 12.so.0.1.2.6
+ * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2
+ * 1.0.17rc1 10 10017 12.so.0.1.0.17rc1
+ * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1
+ * 1.0.17 10 10017 12.so.0.1.0.17
+ * 1.2.7 13 10207 12.so.0.1.2.7
+ * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5
+ * 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5
+ * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5
+ * 1.0.18 10 10018 12.so.0.1.0.18
+ * 1.2.8 13 10208 12.so.0.1.2.8
+ * 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3
+ * 1.2.9beta4-11 13 10209 12.so.0.9[.0]
+ * 1.2.9rc1 13 10209 12.so.0.9[.0]
+ * 1.2.9 13 10209 12.so.0.9[.0]
+ * 1.2.10beta1-7 13 10210 12.so.0.10[.0]
+ * 1.2.10rc1-2 13 10210 12.so.0.10[.0]
+ * 1.2.10 13 10210 12.so.0.10[.0]
+ * 1.4.0beta1-5 14 10400 14.so.0.0[.0]
+ * 1.2.11beta1-4 13 10211 12.so.0.11[.0]
+ * 1.4.0beta7-8 14 10400 14.so.0.0[.0]
+ * 1.2.11 13 10211 12.so.0.11[.0]
+ * 1.2.12 13 10212 12.so.0.12[.0]
+ * 1.4.0beta9-14 14 10400 14.so.0.0[.0]
+ * 1.2.13 13 10213 12.so.0.13[.0]
+ * 1.4.0beta15-36 14 10400 14.so.0.0[.0]
+ * 1.4.0beta37-87 14 10400 14.so.14.0[.0]
+ * 1.4.0rc01 14 10400 14.so.14.0[.0]
+ * 1.4.0beta88-109 14 10400 14.so.14.0[.0]
+ * 1.4.0rc02-08 14 10400 14.so.14.0[.0]
+ * 1.4.0 14 10400 14.so.14.0[.0]
+ * 1.4.1beta01-03 14 10401 14.so.14.1[.0]
+ * 1.4.1rc01 14 10401 14.so.14.1[.0]
+ * 1.4.1beta04-12 14 10401 14.so.14.1[.0]
+ * 1.4.1rc02-04 14 10401 14.so.14.1[.0]
+ * 1.4.1 14 10401 14.so.14.1[.0]
+ * 1.4.2beta01 14 10402 14.so.14.2[.0]
+ * 1.4.2rc02-06 14 10402 14.so.14.2[.0]
+ * 1.4.2 14 10402 14.so.14.2[.0]
+ * 1.4.3beta01-05 14 10403 14.so.14.3[.0]
+ * 1.4.3rc01-03 14 10403 14.so.14.3[.0]
+ * 1.4.3 14 10403 14.so.14.3[.0]
+ * 1.4.4beta01-08 14 10404 14.so.14.4[.0]
+ * 1.4.4rc01-06 14 10404 14.so.14.4[.0]
+ *
+ * Henceforth the source version will match the shared-library major
+ * and minor numbers; the shared-library major version number will be
+ * used for changes in backward compatibility, as it is intended. The
+ * PNG_LIBPNG_VER macro, which is not used within libpng but is available
+ * for applications, is an unsigned integer of the form xyyzz corresponding
+ * to the source version x.y.z (leading zeros in y and z). Beta versions
+ * were given the previous public release number plus a letter, until
+ * version 1.0.6j; from then on they were given the upcoming public
+ * release number plus "betaNN" or "rcN".
+ *
+ * Binary incompatibility exists only when applications make direct access
+ * to the info_ptr or png_ptr members through png.h, and the compiled
+ * application is loaded with a different version of the library.
+ *
+ * DLLNUM will change each time there are forward or backward changes
+ * in binary compatibility (e.g., when a new feature is added).
+ *
+ * See libpng.txt or libpng.3 for more information. The PNG specification
+ * is available as a W3C Recommendation and as an ISO Specification,
+ * <http://www.w3.org/TR/2003/REC-PNG-20031110/
+ */
+
+/*
+ * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+ *
+ * If you modify libpng you may insert additional notices immediately following
+ * this sentence.
+ *
+ * This code is released under the libpng license.
+ *
+ * libpng versions 1.2.6, August 15, 2004, through 1.4.4, September 23, 2010, are
+ * Copyright (c) 2004, 2006-2010 Glenn Randers-Pehrson, and are
+ * distributed according to the same disclaimer and license as libpng-1.2.5
+ * with the following individual added to the list of Contributing Authors:
+ *
+ * Cosmin Truta
+ *
+ * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
+ * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+ * distributed according to the same disclaimer and license as libpng-1.0.6
+ * with the following individuals added to the list of Contributing Authors:
+ *
+ * Simon-Pierre Cadieux
+ * Eric S. Raymond
+ * Gilles Vollant
+ *
+ * and with the following additions to the disclaimer:
+ *
+ * There is no warranty against interference with your enjoyment of the
+ * library or against infringement. There is no warranty that our
+ * efforts or the library will fulfill any of your particular purposes
+ * or needs. This library is provided with all faults, and the entire
+ * risk of satisfactory quality, performance, accuracy, and effort is with
+ * the user.
+ *
+ * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
+ * distributed according to the same disclaimer and license as libpng-0.96,
+ * with the following individuals added to the list of Contributing Authors:
+ *
+ * Tom Lane
+ * Glenn Randers-Pehrson
+ * Willem van Schaik
+ *
+ * libpng versions 0.89, June 1996, through 0.96, May 1997, are
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Distributed according to the same disclaimer and license as libpng-0.88,
+ * with the following individuals added to the list of Contributing Authors:
+ *
+ * John Bowler
+ * Kevin Bracey
+ * Sam Bushell
+ * Magnus Holmgren
+ * Greg Roelofs
+ * Tom Tanner
+ *
+ * libpng versions 0.5, May 1995, through 0.88, January 1996, are
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * For the purposes of this copyright and license, "Contributing Authors"
+ * is defined as the following set of individuals:
+ *
+ * Andreas Dilger
+ * Dave Martindale
+ * Guy Eric Schalnat
+ * Paul Schmidt
+ * Tim Wegner
+ *
+ * The PNG Reference Library is supplied "AS IS". The Contributing Authors
+ * and Group 42, Inc. disclaim all warranties, expressed or implied,
+ * including, without limitation, the warranties of merchantability and of
+ * fitness for any purpose. The Contributing Authors and Group 42, Inc.
+ * assume no liability for direct, indirect, incidental, special, exemplary,
+ * or consequential damages, which may result from the use of the PNG
+ * Reference Library, even if advised of the possibility of such damage.
+ *
+ * Permission is hereby granted to use, copy, modify, and distribute this
+ * source code, or portions hereof, for any purpose, without fee, subject
+ * to the following restrictions:
+ *
+ * 1. The origin of this source code must not be misrepresented.
+ *
+ * 2. Altered versions must be plainly marked as such and
+ * must not be misrepresented as being the original source.
+ *
+ * 3. This Copyright notice may not be removed or altered from
+ * any source or altered source distribution.
+ *
+ * The Contributing Authors and Group 42, Inc. specifically permit, without
+ * fee, and encourage the use of this source code as a component to
+ * supporting the PNG file format in commercial products. If you use this
+ * source code in a product, acknowledgment is not required but would be
+ * appreciated.
+ */
+
+/*
+ * A "png_get_copyright" function is available, for convenient use in "about"
+ * boxes and the like:
+ *
+ * printf("%s",png_get_copyright(NULL));
+ *
+ * Also, the PNG logo (in PNG format, of course) is supplied in the
+ * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+ */
+
+/*
+ * Libpng is OSI Certified Open Source Software. OSI Certified is a
+ * certification mark of the Open Source Initiative.
+ */
+
+/*
+ * The contributing authors would like to thank all those who helped
+ * with testing, bug fixes, and patience. This wouldn't have been
+ * possible without all of you.
+ *
+ * Thanks to Frank J. T. Wojcik for helping with the documentation.
+ */
+
+/*
+ * Y2K compliance in libpng:
+ * =========================
+ *
+ * September 23, 2010
+ *
+ * Since the PNG Development group is an ad-hoc body, we can't make
+ * an official declaration.
+ *
+ * This is your unofficial assurance that libpng from version 0.71 and
+ * upward through 1.4.4 are Y2K compliant. It is my belief that earlier
+ * versions were also Y2K compliant.
+ *
+ * Libpng only has three year fields. One is a 2-byte unsigned integer
+ * that will hold years up to 65535. The other two hold the date in text
+ * format, and will hold years up to 9999.
+ *
+ * The integer is
+ * "png_uint_16 year" in png_time_struct.
+ *
+ * The strings are
+ * "png_charp time_buffer" in png_struct and
+ * "near_time_buffer", which is a local character string in png.c.
+ *
+ * There are seven time-related functions:
+ * png.c: png_convert_to_rfc_1123() in png.c
+ * (formerly png_convert_to_rfc_1152() in error)
+ * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
+ * png_convert_from_time_t() in pngwrite.c
+ * png_get_tIME() in pngget.c
+ * png_handle_tIME() in pngrutil.c, called in pngread.c
+ * png_set_tIME() in pngset.c
+ * png_write_tIME() in pngwutil.c, called in pngwrite.c
+ *
+ * All handle dates properly in a Y2K environment. The
+ * png_convert_from_time_t() function calls gmtime() to convert from system
+ * clock time, which returns (year - 1900), which we properly convert to
+ * the full 4-digit year. There is a possibility that applications using
+ * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+ * function, or that they are incorrectly passing only a 2-digit year
+ * instead of "year - 1900" into the png_convert_from_struct_tm() function,
+ * but this is not under our control. The libpng documentation has always
+ * stated that it works with 4-digit years, and the APIs have been
+ * documented as such.
+ *
+ * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
+ * integer to hold the year, and can hold years as large as 65535.
+ *
+ * zlib, upon which libpng depends, is also Y2K compliant. It contains
+ * no date-related code.
+ *
+ * Glenn Randers-Pehrson
+ * libpng maintainer
+ * PNG Development Group
+ */
+
+#ifndef PNG_H
+#define PNG_H
+
+/* This is not the place to learn how to use libpng. The file libpng.txt
+ * describes how to use libpng, and the file example.c summarizes it
+ * with some code on which to build. This file is useful for looking
+ * at the actual function definitions and structure components.
+ */
+
+/* Version information for png.h - this should match the version in png.c */
+#define PNG_LIBPNG_VER_STRING "1.4.4"
+#define PNG_HEADER_VERSION_STRING \
+ " libpng version 1.4.4 - September 23, 2010\n"
+
+#define PNG_LIBPNG_VER_SONUM 14
+#define PNG_LIBPNG_VER_DLLNUM 14
+
+/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
+#define PNG_LIBPNG_VER_MAJOR 1
+#define PNG_LIBPNG_VER_MINOR 4
+#define PNG_LIBPNG_VER_RELEASE 4
+/* This should match the numeric part of the final component of
+ * PNG_LIBPNG_VER_STRING, omitting any leading zero:
+ */
+
+#define PNG_LIBPNG_VER_BUILD 0
+
+/* Release Status */
+#define PNG_LIBPNG_BUILD_ALPHA 1
+#define PNG_LIBPNG_BUILD_BETA 2
+#define PNG_LIBPNG_BUILD_RC 3
+#define PNG_LIBPNG_BUILD_STABLE 4
+#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
+
+/* Release-Specific Flags */
+#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
+ PNG_LIBPNG_BUILD_STABLE only */
+#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
+ PNG_LIBPNG_BUILD_SPECIAL */
+#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
+ PNG_LIBPNG_BUILD_PRIVATE */
+
+#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
+
+/* Careful here. At one time, Guy wanted to use 082, but that would be octal.
+ * We must not include leading zeros.
+ * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
+ * version 1.0.0 was mis-numbered 100 instead of 10000). From
+ * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
+ */
+#define PNG_LIBPNG_VER 10404 /* 1.4.4 */
+
+#ifndef PNG_VERSION_INFO_ONLY
+/* Include the compression library's header */
+#include "zlib.h"
+#endif
+
+/* Include all user configurable info, including optional assembler routines */
+#include "pngconf.h"
+
+/*
+ * Added at libpng-1.2.8
+ *
+ * Ref MSDN: Private as priority over Special
+ * VS_FF_PRIVATEBUILD File *was not* built using standard release
+ * procedures. If this value is given, the StringFileInfo block must
+ * contain a PrivateBuild string.
+ *
+ * VS_FF_SPECIALBUILD File *was* built by the original company using
+ * standard release procedures but is a variation of the standard
+ * file of the same version number. If this value is given, the
+ * StringFileInfo block must contain a SpecialBuild string.
+ */
+
+#ifdef PNG_USER_PRIVATEBUILD
+# define PNG_LIBPNG_BUILD_TYPE \
+ (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
+#else
+# ifdef PNG_LIBPNG_SPECIALBUILD
+# define PNG_LIBPNG_BUILD_TYPE \
+ (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
+# else
+# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
+# endif
+#endif
+
+#ifndef PNG_VERSION_INFO_ONLY
+
+/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/* This file is arranged in several sections. The first section contains
+ * structure and type definitions. The second section contains the external
+ * library functions, while the third has the internal library functions,
+ * which applications aren't expected to use directly.
+ */
+
+/* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
+#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
+/* Version information for C files, stored in png.c. This had better match
+ * the version above.
+ */
+#define png_libpng_ver png_get_header_ver(NULL)
+
+#endif /* PNG_NO_EXTERN */
+
+/* Three color definitions. The order of the red, green, and blue, (and the
+ * exact size) is not important, although the size of the fields need to
+ * be png_byte or png_uint_16 (as defined below).
+ */
+typedef struct png_color_struct
+{
+ png_byte red;
+ png_byte green;
+ png_byte blue;
+} png_color;
+typedef png_color FAR * png_colorp;
+typedef png_color FAR * FAR * png_colorpp;
+
+typedef struct png_color_16_struct
+{
+ png_byte index; /* used for palette files */
+ png_uint_16 red; /* for use in red green blue files */
+ png_uint_16 green;
+ png_uint_16 blue;
+ png_uint_16 gray; /* for use in grayscale files */
+} png_color_16;
+typedef png_color_16 FAR * png_color_16p;
+typedef png_color_16 FAR * FAR * png_color_16pp;
+
+typedef struct png_color_8_struct
+{
+ png_byte red; /* for use in red green blue files */
+ png_byte green;
+ png_byte blue;
+ png_byte gray; /* for use in grayscale files */
+ png_byte alpha; /* for alpha channel files */
+} png_color_8;
+typedef png_color_8 FAR * png_color_8p;
+typedef png_color_8 FAR * FAR * png_color_8pp;
+
+/*
+ * The following two structures are used for the in-core representation
+ * of sPLT chunks.
+ */
+typedef struct png_sPLT_entry_struct
+{
+ png_uint_16 red;
+ png_uint_16 green;
+ png_uint_16 blue;
+ png_uint_16 alpha;
+ png_uint_16 frequency;
+} png_sPLT_entry;
+typedef png_sPLT_entry FAR * png_sPLT_entryp;
+typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
+
+/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
+ * occupy the LSB of their respective members, and the MSB of each member
+ * is zero-filled. The frequency member always occupies the full 16 bits.
+ */
+
+typedef struct png_sPLT_struct
+{
+ png_charp name; /* palette name */
+ png_byte depth; /* depth of palette samples */
+ png_sPLT_entryp entries; /* palette entries */
+ png_int_32 nentries; /* number of palette entries */
+} png_sPLT_t;
+typedef png_sPLT_t FAR * png_sPLT_tp;
+typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
+
+#ifdef PNG_TEXT_SUPPORTED
+/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
+ * and whether that contents is compressed or not. The "key" field
+ * points to a regular zero-terminated C string. The "text", "lang", and
+ * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
+ * However, the * structure returned by png_get_text() will always contain
+ * regular zero-terminated C strings (possibly empty), never NULL pointers,
+ * so they can be safely used in printf() and other string-handling functions.
+ */
+typedef struct png_text_struct
+{
+ int compression; /* compression value:
+ -1: tEXt, none
+ 0: zTXt, deflate
+ 1: iTXt, none
+ 2: iTXt, deflate */
+ png_charp key; /* keyword, 1-79 character description of "text" */
+ png_charp text; /* comment, may be an empty string (ie "")
+ or a NULL pointer */
+ png_size_t text_length; /* length of the text string */
+#ifdef PNG_iTXt_SUPPORTED
+ png_size_t itxt_length; /* length of the itxt string */
+ png_charp lang; /* language code, 0-79 characters
+ or a NULL pointer */
+ png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
+ chars or a NULL pointer */
+#endif
+} png_text;
+typedef png_text FAR * png_textp;
+typedef png_text FAR * FAR * png_textpp;
+#endif
+
+/* Supported compression types for text in PNG files (tEXt, and zTXt).
+ * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
+#define PNG_TEXT_COMPRESSION_NONE_WR -3
+#define PNG_TEXT_COMPRESSION_zTXt_WR -2
+#define PNG_TEXT_COMPRESSION_NONE -1
+#define PNG_TEXT_COMPRESSION_zTXt 0
+#define PNG_ITXT_COMPRESSION_NONE 1
+#define PNG_ITXT_COMPRESSION_zTXt 2
+#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
+
+/* png_time is a way to hold the time in an machine independent way.
+ * Two conversions are provided, both from time_t and struct tm. There
+ * is no portable way to convert to either of these structures, as far
+ * as I know. If you know of a portable way, send it to me. As a side
+ * note - PNG has always been Year 2000 compliant!
+ */
+typedef struct png_time_struct
+{
+ png_uint_16 year; /* full year, as in, 1995 */
+ png_byte month; /* month of year, 1 - 12 */
+ png_byte day; /* day of month, 1 - 31 */
+ png_byte hour; /* hour of day, 0 - 23 */
+ png_byte minute; /* minute of hour, 0 - 59 */
+ png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
+} png_time;
+typedef png_time FAR * png_timep;
+typedef png_time FAR * FAR * png_timepp;
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
+ defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+/* png_unknown_chunk is a structure to hold queued chunks for which there is
+ * no specific support. The idea is that we can use this to queue
+ * up private chunks for output even though the library doesn't actually
+ * know about their semantics.
+ */
+typedef struct png_unknown_chunk_t
+{
+ png_byte name[5];
+ png_byte *data;
+ png_size_t size;
+
+ /* libpng-using applications should NOT directly modify this byte. */
+ png_byte location; /* mode of operation at read time */
+}
+png_unknown_chunk;
+typedef png_unknown_chunk FAR * png_unknown_chunkp;
+typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
+#endif
+
+/* png_info is a structure that holds the information in a PNG file so
+ * that the application can find out the characteristics of the image.
+ * If you are reading the file, this structure will tell you what is
+ * in the PNG file. If you are writing the file, fill in the information
+ * you want to put into the PNG file, then call png_write_info().
+ * The names chosen should be very close to the PNG specification, so
+ * consult that document for information about the meaning of each field.
+ *
+ * With libpng < 0.95, it was only possible to directly set and read the
+ * the values in the png_info_struct, which meant that the contents and
+ * order of the values had to remain fixed. With libpng 0.95 and later,
+ * however, there are now functions that abstract the contents of
+ * png_info_struct from the application, so this makes it easier to use
+ * libpng with dynamic libraries, and even makes it possible to use
+ * libraries that don't have all of the libpng ancillary chunk-handing
+ * functionality.
+ *
+ * In any case, the order of the parameters in png_info_struct should NOT
+ * be changed for as long as possible to keep compatibility with applications
+ * that use the old direct-access method with png_info_struct.
+ *
+ * The following members may have allocated storage attached that should be
+ * cleaned up before the structure is discarded: palette, trans, text,
+ * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
+ * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
+ * are automatically freed when the info structure is deallocated, if they were
+ * allocated internally by libpng. This behavior can be changed by means
+ * of the png_data_freer() function.
+ *
+ * More allocation details: all the chunk-reading functions that
+ * change these members go through the corresponding png_set_*
+ * functions. A function to clear these members is available: see
+ * png_free_data(). The png_set_* functions do not depend on being
+ * able to point info structure members to any of the storage they are
+ * passed (they make their own copies), EXCEPT that the png_set_text
+ * functions use the same storage passed to them in the text_ptr or
+ * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
+ * functions do not make their own copies.
+ */
+typedef struct png_info_struct
+{
+ /* the following are necessary for every PNG file */
+ png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels (from IHDR) */
+ png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels (from IHDR) */
+ png_uint_32 valid PNG_DEPSTRUCT; /* valid chunk data (see PNG_INFO_
+ below) */
+ png_size_t rowbytes PNG_DEPSTRUCT; /* bytes needed to hold an untransformed
+ row */
+ png_colorp palette PNG_DEPSTRUCT; /* array of color values
+ (valid & PNG_INFO_PLTE) */
+ png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in
+ "palette" (PLTE) */
+ png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparent palette
+ color (tRNS) */
+ png_byte bit_depth PNG_DEPSTRUCT; /* 1, 2, 4, 8, or 16 bits/channel
+ (from IHDR) */
+ png_byte color_type PNG_DEPSTRUCT; /* see PNG_COLOR_TYPE_ below
+ (from IHDR) */
+ /* The following three should have been named *_method not *_type */
+ png_byte compression_type PNG_DEPSTRUCT; /* must be
+ PNG_COMPRESSION_TYPE_BASE (IHDR) */
+ png_byte filter_type PNG_DEPSTRUCT; /* must be PNG_FILTER_TYPE_BASE
+ (from IHDR) */
+ png_byte interlace_type PNG_DEPSTRUCT; /* One of PNG_INTERLACE_NONE,
+ PNG_INTERLACE_ADAM7 */
+
+ /* The following is informational only on read, and not used on writes. */
+ png_byte channels PNG_DEPSTRUCT; /* number of data channels per
+ pixel (1, 2, 3, 4) */
+ png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
+ png_byte spare_byte PNG_DEPSTRUCT; /* to align the data, and for
+ future use */
+ png_byte signature[8] PNG_DEPSTRUCT; /* magic bytes read by libpng
+ from start of file */
+
+ /* The rest of the data is optional. If you are reading, check the
+ * valid field to see if the information in these are valid. If you
+ * are writing, set the valid field to those chunks you want written,
+ * and initialize the appropriate fields below.
+ */
+
+#if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
+ /* The gAMA chunk describes the gamma characteristics of the system
+ * on which the image was created, normally in the range [1.0, 2.5].
+ * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
+ */
+ float gamma PNG_DEPSTRUCT; /* gamma value of image,
+ if (valid & PNG_INFO_gAMA) */
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+ /* GR-P, 0.96a */
+ /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
+ png_byte srgb_intent PNG_DEPSTRUCT; /* sRGB rendering intent
+ [0, 1, 2, or 3] */
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+ /* The tEXt, and zTXt chunks contain human-readable textual data in
+ * uncompressed, compressed, and optionally compressed forms, respectively.
+ * The data in "text" is an array of pointers to uncompressed,
+ * null-terminated C strings. Each chunk has a keyword that describes the
+ * textual data contained in that chunk. Keywords are not required to be
+ * unique, and the text string may be empty. Any number of text chunks may
+ * be in an image.
+ */
+ int num_text PNG_DEPSTRUCT; /* number of comments read/to write */
+ int max_text PNG_DEPSTRUCT; /* current size of text array */
+ png_textp text PNG_DEPSTRUCT; /* array of comments read/to write */
+#endif /* PNG_TEXT_SUPPORTED */
+
+#ifdef PNG_tIME_SUPPORTED
+ /* The tIME chunk holds the last time the displayed image data was
+ * modified. See the png_time struct for the contents of this struct.
+ */
+ png_time mod_time PNG_DEPSTRUCT;
+#endif
+
+#ifdef PNG_sBIT_SUPPORTED
+ /* The sBIT chunk specifies the number of significant high-order bits
+ * in the pixel data. Values are in the range [1, bit_depth], and are
+ * only specified for the channels in the pixel data. The contents of
+ * the low-order bits is not specified. Data is valid if
+ * (valid & PNG_INFO_sBIT) is non-zero.
+ */
+ png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in color channels */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
+defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* The tRNS chunk supplies transparency data for paletted images and
+ * other image types that don't need a full alpha channel. There are
+ * "num_trans" transparency values for a paletted image, stored in the
+ * same order as the palette colors, starting from index 0. Values
+ * for the data are in the range [0, 255], ranging from fully transparent
+ * to fully opaque, respectively. For non-paletted images, there is a
+ * single color specified that should be treated as fully transparent.
+ * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
+ */
+ png_bytep trans_alpha PNG_DEPSTRUCT; /* alpha values for paletted
+ image */
+ png_color_16 trans_color PNG_DEPSTRUCT; /* transparent color for
+ non-palette image */
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* The bKGD chunk gives the suggested image background color if the
+ * display program does not have its own background color and the image
+ * is needs to composited onto a background before display. The colors
+ * in "background" are normally in the same color space/depth as the
+ * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
+ */
+ png_color_16 background PNG_DEPSTRUCT;
+#endif
+
+#ifdef PNG_oFFs_SUPPORTED
+ /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
+ * and downwards from the top-left corner of the display, page, or other
+ * application-specific co-ordinate space. See the PNG_OFFSET_ defines
+ * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
+ */
+ png_int_32 x_offset PNG_DEPSTRUCT; /* x offset on page */
+ png_int_32 y_offset PNG_DEPSTRUCT; /* y offset on page */
+ png_byte offset_unit_type PNG_DEPSTRUCT; /* offset units type */
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+ /* The pHYs chunk gives the physical pixel density of the image for
+ * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
+ * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
+ */
+ png_uint_32 x_pixels_per_unit PNG_DEPSTRUCT; /* horizontal pixel density */
+ png_uint_32 y_pixels_per_unit PNG_DEPSTRUCT; /* vertical pixel density */
+ png_byte phys_unit_type PNG_DEPSTRUCT; /* resolution type (see
+ PNG_RESOLUTION_ below) */
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+ /* The hIST chunk contains the relative frequency or importance of the
+ * various palette entries, so that a viewer can intelligently select a
+ * reduced-color palette, if required. Data is an array of "num_palette"
+ * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
+ * is non-zero.
+ */
+ png_uint_16p hist PNG_DEPSTRUCT;
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+ /* The cHRM chunk describes the CIE color characteristics of the monitor
+ * on which the PNG was created. This data allows the viewer to do gamut
+ * mapping of the input image to ensure that the viewer sees the same
+ * colors in the image as the creator. Values are in the range
+ * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
+ */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ float x_white PNG_DEPSTRUCT;
+ float y_white PNG_DEPSTRUCT;
+ float x_red PNG_DEPSTRUCT;
+ float y_red PNG_DEPSTRUCT;
+ float x_green PNG_DEPSTRUCT;
+ float y_green PNG_DEPSTRUCT;
+ float x_blue PNG_DEPSTRUCT;
+ float y_blue PNG_DEPSTRUCT;
+#endif
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+ /* The pCAL chunk describes a transformation between the stored pixel
+ * values and original physical data values used to create the image.
+ * The integer range [0, 2^bit_depth - 1] maps to the floating-point
+ * range given by [pcal_X0, pcal_X1], and are further transformed by a
+ * (possibly non-linear) transformation function given by "pcal_type"
+ * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
+ * defines below, and the PNG-Group's PNG extensions document for a
+ * complete description of the transformations and how they should be
+ * implemented, and for a description of the ASCII parameter strings.
+ * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
+ */
+ png_charp pcal_purpose PNG_DEPSTRUCT; /* pCAL chunk description string */
+ png_int_32 pcal_X0 PNG_DEPSTRUCT; /* minimum value */
+ png_int_32 pcal_X1 PNG_DEPSTRUCT; /* maximum value */
+ png_charp pcal_units PNG_DEPSTRUCT; /* Latin-1 string giving physical
+ units */
+ png_charpp pcal_params PNG_DEPSTRUCT; /* ASCII strings containing
+ parameter values */
+ png_byte pcal_type PNG_DEPSTRUCT; /* equation type
+ (see PNG_EQUATION_ below) */
+ png_byte pcal_nparams PNG_DEPSTRUCT; /* number of parameters given
+ in pcal_params */
+#endif
+
+/* New members added in libpng-1.0.6 */
+ png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is
+ responsible for freeing */
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
+ defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+ /* Storage for unknown chunks that the library doesn't recognize. */
+ png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT;
+ png_size_t unknown_chunks_num PNG_DEPSTRUCT;
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+ /* iCCP chunk data. */
+ png_charp iccp_name PNG_DEPSTRUCT; /* profile name */
+ png_charp iccp_profile PNG_DEPSTRUCT; /* International Color Consortium
+ profile data */
+ /* Note to maintainer: should be png_bytep */
+ png_uint_32 iccp_proflen PNG_DEPSTRUCT; /* ICC profile data length */
+ png_byte iccp_compression PNG_DEPSTRUCT; /* Always zero */
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+ /* Data on sPLT chunks (there may be more than one). */
+ png_sPLT_tp splt_palettes PNG_DEPSTRUCT;
+ png_uint_32 splt_palettes_num PNG_DEPSTRUCT;
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+ /* The sCAL chunk describes the actual physical dimensions of the
+ * subject matter of the graphic. The chunk contains a unit specification
+ * a byte value, and two ASCII strings representing floating-point
+ * values. The values are width and height corresponsing to one pixel
+ * in the image. This external representation is converted to double
+ * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
+ */
+ png_byte scal_unit PNG_DEPSTRUCT; /* unit of physical scale */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ double scal_pixel_width PNG_DEPSTRUCT; /* width of one pixel */
+ double scal_pixel_height PNG_DEPSTRUCT; /* height of one pixel */
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_charp scal_s_width PNG_DEPSTRUCT; /* string containing height */
+ png_charp scal_s_height PNG_DEPSTRUCT; /* string containing width */
+#endif
+#endif
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+ /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
+ non-zero */
+ /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
+ png_bytepp row_pointers PNG_DEPSTRUCT; /* the image bits */
+#endif
+
+#if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
+ png_fixed_point int_gamma PNG_DEPSTRUCT; /* gamma of image,
+ if (valid & PNG_INFO_gAMA) */
+#endif
+
+#if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
+ png_fixed_point int_x_white PNG_DEPSTRUCT;
+ png_fixed_point int_y_white PNG_DEPSTRUCT;
+ png_fixed_point int_x_red PNG_DEPSTRUCT;
+ png_fixed_point int_y_red PNG_DEPSTRUCT;
+ png_fixed_point int_x_green PNG_DEPSTRUCT;
+ png_fixed_point int_y_green PNG_DEPSTRUCT;
+ png_fixed_point int_x_blue PNG_DEPSTRUCT;
+ png_fixed_point int_y_blue PNG_DEPSTRUCT;
+#endif
+
+} png_info;
+
+typedef png_info FAR * png_infop;
+typedef png_info FAR * FAR * png_infopp;
+
+/* Maximum positive integer used in PNG is (2^31)-1 */
+#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
+#define PNG_UINT_32_MAX ((png_uint_32)(-1))
+#define PNG_SIZE_MAX ((png_size_t)(-1))
+
+/* These describe the color_type field in png_info. */
+/* color type masks */
+#define PNG_COLOR_MASK_PALETTE 1
+#define PNG_COLOR_MASK_COLOR 2
+#define PNG_COLOR_MASK_ALPHA 4
+
+/* color types. Note that not all combinations are legal */
+#define PNG_COLOR_TYPE_GRAY 0
+#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
+#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
+#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
+#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
+/* aliases */
+#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
+#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
+
+/* This is for compression type. PNG 1.0-1.2 only define the single type. */
+#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
+#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
+
+/* This is for filter type. PNG 1.0-1.2 only define the single type. */
+#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
+#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
+#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
+
+/* These are for the interlacing type. These values should NOT be changed. */
+#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
+#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
+#define PNG_INTERLACE_LAST 2 /* Not a valid value */
+
+/* These are for the oFFs chunk. These values should NOT be changed. */
+#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
+#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
+#define PNG_OFFSET_LAST 2 /* Not a valid value */
+
+/* These are for the pCAL chunk. These values should NOT be changed. */
+#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
+#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
+#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
+#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
+#define PNG_EQUATION_LAST 4 /* Not a valid value */
+
+/* These are for the sCAL chunk. These values should NOT be changed. */
+#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
+#define PNG_SCALE_METER 1 /* meters per pixel */
+#define PNG_SCALE_RADIAN 2 /* radians per pixel */
+#define PNG_SCALE_LAST 3 /* Not a valid value */
+
+/* These are for the pHYs chunk. These values should NOT be changed. */
+#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
+#define PNG_RESOLUTION_METER 1 /* pixels/meter */
+#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
+
+/* These are for the sRGB chunk. These values should NOT be changed. */
+#define PNG_sRGB_INTENT_PERCEPTUAL 0
+#define PNG_sRGB_INTENT_RELATIVE 1
+#define PNG_sRGB_INTENT_SATURATION 2
+#define PNG_sRGB_INTENT_ABSOLUTE 3
+#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
+
+/* This is for text chunks */
+#define PNG_KEYWORD_MAX_LENGTH 79
+
+/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
+#define PNG_MAX_PALETTE_LENGTH 256
+
+/* These determine if an ancillary chunk's data has been successfully read
+ * from the PNG header, or if the application has filled in the corresponding
+ * data in the info_struct to be written into the output file. The values
+ * of the PNG_INFO_<chunk> defines should NOT be changed.
+ */
+#define PNG_INFO_gAMA 0x0001
+#define PNG_INFO_sBIT 0x0002
+#define PNG_INFO_cHRM 0x0004
+#define PNG_INFO_PLTE 0x0008
+#define PNG_INFO_tRNS 0x0010
+#define PNG_INFO_bKGD 0x0020
+#define PNG_INFO_hIST 0x0040
+#define PNG_INFO_pHYs 0x0080
+#define PNG_INFO_oFFs 0x0100
+#define PNG_INFO_tIME 0x0200
+#define PNG_INFO_pCAL 0x0400
+#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
+#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
+#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
+#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
+#define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
+
+/* This is used for the transformation routines, as some of them
+ * change these values for the row. It also should enable using
+ * the routines for other purposes.
+ */
+typedef struct png_row_info_struct
+{
+ png_uint_32 width; /* width of row */
+ png_size_t rowbytes; /* number of bytes in row */
+ png_byte color_type; /* color type of row */
+ png_byte bit_depth; /* bit depth of row */
+ png_byte channels; /* number of channels (1, 2, 3, or 4) */
+ png_byte pixel_depth; /* bits per pixel (depth * channels) */
+} png_row_info;
+
+typedef png_row_info FAR * png_row_infop;
+typedef png_row_info FAR * FAR * png_row_infopp;
+
+/* These are the function types for the I/O functions and for the functions
+ * that allow the user to override the default I/O functions with his or her
+ * own. The png_error_ptr type should match that of user-supplied warning
+ * and error functions, while the png_rw_ptr type should match that of the
+ * user read/write data functions.
+ */
+typedef struct png_struct_def png_struct;
+typedef png_struct FAR * png_structp;
+
+typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
+typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
+typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
+typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
+ int));
+typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
+ int));
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp,
+ png_infop));
+typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
+typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
+ png_uint_32, int));
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
+ png_row_infop, png_bytep));
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp,
+ png_unknown_chunkp));
+#endif
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
+#endif
+#ifdef PNG_SETJMP_SUPPORTED
+/* This must match the function definition in <setjmp.h>, and the
+ * application must include this before png.h to obtain the definition
+ * of jmp_buf.
+ */
+typedef void (PNGAPI *png_longjmp_ptr) PNGARG((jmp_buf, int));
+#endif
+
+/* Transform masks for the high-level interface */
+#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
+#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
+#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
+#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
+#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
+#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
+#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
+#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
+#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
+#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
+#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
+#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
+#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
+/* Added to libpng-1.2.34 */
+#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
+#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
+/* Added to libpng-1.4.0 */
+#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
+
+/* Flags for MNG supported features */
+#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
+#define PNG_FLAG_MNG_FILTER_64 0x04
+#define PNG_ALL_MNG_FEATURES 0x05
+
+typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_alloc_size_t));
+typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
+
+/* The structure that holds the information to read and write PNG files.
+ * The only people who need to care about what is inside of this are the
+ * people who will be modifying the library for their own special needs.
+ * It should NOT be accessed directly by an application, except to store
+ * the jmp_buf.
+ */
+
+struct png_struct_def
+{
+#ifdef PNG_SETJMP_SUPPORTED
+ jmp_buf jmpbuf PNG_DEPSTRUCT; /* used in png_error */
+ png_longjmp_ptr longjmp_fn PNG_DEPSTRUCT;/* setjmp non-local goto
+ function. */
+#endif
+ png_error_ptr error_fn PNG_DEPSTRUCT; /* function for printing
+ errors and aborting */
+ png_error_ptr warning_fn PNG_DEPSTRUCT; /* function for printing
+ warnings */
+ png_voidp error_ptr PNG_DEPSTRUCT; /* user supplied struct for
+ error functions */
+ png_rw_ptr write_data_fn PNG_DEPSTRUCT; /* function for writing
+ output data */
+ png_rw_ptr read_data_fn PNG_DEPSTRUCT; /* function for reading
+ input data */
+ png_voidp io_ptr PNG_DEPSTRUCT; /* ptr to application struct
+ for I/O functions */
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ png_user_transform_ptr read_user_transform_fn PNG_DEPSTRUCT; /* user read
+ transform */
+#endif
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+ png_user_transform_ptr write_user_transform_fn PNG_DEPSTRUCT; /* user write
+ transform */
+#endif
+
+/* These were added in libpng-1.0.2 */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+ png_voidp user_transform_ptr PNG_DEPSTRUCT; /* user supplied struct
+ for user transform */
+ png_byte user_transform_depth PNG_DEPSTRUCT; /* bit depth of user
+ transformed pixels */
+ png_byte user_transform_channels PNG_DEPSTRUCT; /* channels in user
+ transformed pixels */
+#endif
+#endif
+
+ png_uint_32 mode PNG_DEPSTRUCT; /* tells us where we are in
+ the PNG file */
+ png_uint_32 flags PNG_DEPSTRUCT; /* flags indicating various
+ things to libpng */
+ png_uint_32 transformations PNG_DEPSTRUCT; /* which transformations
+ to perform */
+
+ z_stream zstream PNG_DEPSTRUCT; /* pointer to decompression
+ structure (below) */
+ png_bytep zbuf PNG_DEPSTRUCT; /* buffer for zlib */
+ png_size_t zbuf_size PNG_DEPSTRUCT; /* size of zbuf */
+ int zlib_level PNG_DEPSTRUCT; /* holds zlib compression level */
+ int zlib_method PNG_DEPSTRUCT; /* holds zlib compression method */
+ int zlib_window_bits PNG_DEPSTRUCT; /* holds zlib compression window
+ bits */
+ int zlib_mem_level PNG_DEPSTRUCT; /* holds zlib compression memory
+ level */
+ int zlib_strategy PNG_DEPSTRUCT; /* holds zlib compression
+ strategy */
+
+ png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels */
+ png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels */
+ png_uint_32 num_rows PNG_DEPSTRUCT; /* number of rows in current pass */
+ png_uint_32 usr_width PNG_DEPSTRUCT; /* width of row at start of write */
+ png_size_t rowbytes PNG_DEPSTRUCT; /* size of row in bytes */
+#if 0 /* Replaced with the following in libpng-1.4.1 */
+ png_size_t irowbytes PNG_DEPSTRUCT;
+#endif
+/* Added in libpng-1.4.1 */
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
+ * can occupy when decompressed. 0 means unlimited.
+ * We will change the typedef from png_size_t to png_alloc_size_t
+ * in libpng-1.6.0
+ */
+ png_alloc_size_t user_chunk_malloc_max PNG_DEPSTRUCT;
+#endif
+ png_uint_32 iwidth PNG_DEPSTRUCT; /* width of current interlaced
+ row in pixels */
+ png_uint_32 row_number PNG_DEPSTRUCT; /* current row in interlace pass */
+ png_bytep prev_row PNG_DEPSTRUCT; /* buffer to save previous
+ (unfiltered) row */
+ png_bytep row_buf PNG_DEPSTRUCT; /* buffer to save current
+ (unfiltered) row */
+ png_bytep sub_row PNG_DEPSTRUCT; /* buffer to save "sub" row
+ when filtering */
+ png_bytep up_row PNG_DEPSTRUCT; /* buffer to save "up" row
+ when filtering */
+ png_bytep avg_row PNG_DEPSTRUCT; /* buffer to save "avg" row
+ when filtering */
+ png_bytep paeth_row PNG_DEPSTRUCT; /* buffer to save "Paeth" row
+ when filtering */
+ png_row_info row_info PNG_DEPSTRUCT; /* used for transformation
+ routines */
+
+ png_uint_32 idat_size PNG_DEPSTRUCT; /* current IDAT size for read */
+ png_uint_32 crc PNG_DEPSTRUCT; /* current chunk CRC value */
+ png_colorp palette PNG_DEPSTRUCT; /* palette from the input file */
+ png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in
+ palette */
+ png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparency values */
+ png_byte chunk_name[5] PNG_DEPSTRUCT; /* null-terminated name of current
+ chunk */
+ png_byte compression PNG_DEPSTRUCT; /* file compression type
+ (always 0) */
+ png_byte filter PNG_DEPSTRUCT; /* file filter type (always 0) */
+ png_byte interlaced PNG_DEPSTRUCT; /* PNG_INTERLACE_NONE,
+ PNG_INTERLACE_ADAM7 */
+ png_byte pass PNG_DEPSTRUCT; /* current interlace pass (0 - 6) */
+ png_byte do_filter PNG_DEPSTRUCT; /* row filter flags (see
+ PNG_FILTER_ below ) */
+ png_byte color_type PNG_DEPSTRUCT; /* color type of file */
+ png_byte bit_depth PNG_DEPSTRUCT; /* bit depth of file */
+ png_byte usr_bit_depth PNG_DEPSTRUCT; /* bit depth of users row */
+ png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
+ png_byte channels PNG_DEPSTRUCT; /* number of channels in file */
+ png_byte usr_channels PNG_DEPSTRUCT; /* channels at start of write */
+ png_byte sig_bytes PNG_DEPSTRUCT; /* magic bytes read/written from
+ start of file */
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+ png_uint_16 filler PNG_DEPSTRUCT; /* filler bytes for pixel
+ expansion */
+#endif
+
+#ifdef PNG_bKGD_SUPPORTED
+ png_byte background_gamma_type PNG_DEPSTRUCT;
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+ float background_gamma PNG_DEPSTRUCT;
+# endif
+ png_color_16 background PNG_DEPSTRUCT; /* background color in
+ screen gamma space */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ png_color_16 background_1 PNG_DEPSTRUCT; /* background normalized
+ to gamma 1.0 */
+#endif
+#endif /* PNG_bKGD_SUPPORTED */
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+ png_flush_ptr output_flush_fn PNG_DEPSTRUCT; /* Function for flushing
+ output */
+ png_uint_32 flush_dist PNG_DEPSTRUCT; /* how many rows apart to flush,
+ 0 - no flush */
+ png_uint_32 flush_rows PNG_DEPSTRUCT; /* number of rows written since
+ last flush */
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ int gamma_shift PNG_DEPSTRUCT; /* number of "insignificant" bits
+ 16-bit gamma */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ float gamma PNG_DEPSTRUCT; /* file gamma value */
+ float screen_gamma PNG_DEPSTRUCT; /* screen gamma value
+ (display_exponent) */
+#endif
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ png_bytep gamma_table PNG_DEPSTRUCT; /* gamma table for 8-bit
+ depth files */
+ png_bytep gamma_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
+ png_bytep gamma_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
+ png_uint_16pp gamma_16_table PNG_DEPSTRUCT; /* gamma table for 16-bit
+ depth files */
+ png_uint_16pp gamma_16_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to
+ screen */
+ png_uint_16pp gamma_16_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
+ png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in each
+ available channel */
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+ png_color_8 shift PNG_DEPSTRUCT; /* shift for significant bit
+ tranformation */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
+ || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ png_bytep trans_alpha PNG_DEPSTRUCT; /* alpha values for
+ paletted files */
+ png_color_16 trans_color PNG_DEPSTRUCT; /* transparent color for
+ non-paletted files */
+#endif
+
+ png_read_status_ptr read_row_fn PNG_DEPSTRUCT; /* called after each
+ row is decoded */
+ png_write_status_ptr write_row_fn PNG_DEPSTRUCT; /* called after each
+ row is encoded */
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+ png_progressive_info_ptr info_fn PNG_DEPSTRUCT; /* called after header
+ data fully read */
+ png_progressive_row_ptr row_fn PNG_DEPSTRUCT; /* called after each
+ prog. row is decoded */
+ png_progressive_end_ptr end_fn PNG_DEPSTRUCT; /* called after image
+ is complete */
+ png_bytep save_buffer_ptr PNG_DEPSTRUCT; /* current location in
+ save_buffer */
+ png_bytep save_buffer PNG_DEPSTRUCT; /* buffer for previously
+ read data */
+ png_bytep current_buffer_ptr PNG_DEPSTRUCT; /* current location in
+ current_buffer */
+ png_bytep current_buffer PNG_DEPSTRUCT; /* buffer for recently
+ used data */
+ png_uint_32 push_length PNG_DEPSTRUCT; /* size of current input
+ chunk */
+ png_uint_32 skip_length PNG_DEPSTRUCT; /* bytes to skip in
+ input data */
+ png_size_t save_buffer_size PNG_DEPSTRUCT; /* amount of data now
+ in save_buffer */
+ png_size_t save_buffer_max PNG_DEPSTRUCT; /* total size of
+ save_buffer */
+ png_size_t buffer_size PNG_DEPSTRUCT; /* total amount of
+ available input data */
+ png_size_t current_buffer_size PNG_DEPSTRUCT; /* amount of data now
+ in current_buffer */
+ int process_mode PNG_DEPSTRUCT; /* what push library
+ is currently doing */
+ int cur_palette PNG_DEPSTRUCT; /* current push library
+ palette index */
+
+# ifdef PNG_TEXT_SUPPORTED
+ png_size_t current_text_size PNG_DEPSTRUCT; /* current size of
+ text input data */
+ png_size_t current_text_left PNG_DEPSTRUCT; /* how much text left
+ to read in input */
+ png_charp current_text PNG_DEPSTRUCT; /* current text chunk
+ buffer */
+ png_charp current_text_ptr PNG_DEPSTRUCT; /* current location
+ in current_text */
+# endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
+
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+
+#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
+/* For the Borland special 64K segment handler */
+ png_bytepp offset_table_ptr PNG_DEPSTRUCT;
+ png_bytep offset_table PNG_DEPSTRUCT;
+ png_uint_16 offset_table_number PNG_DEPSTRUCT;
+ png_uint_16 offset_table_count PNG_DEPSTRUCT;
+ png_uint_16 offset_table_count_free PNG_DEPSTRUCT;
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ png_bytep palette_lookup PNG_DEPSTRUCT; /* lookup table for quantizing */
+ png_bytep quantize_index PNG_DEPSTRUCT; /* index translation for palette
+ files */
+#endif
+
+#if defined(PNG_READ_QUANTIZE_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
+ png_uint_16p hist PNG_DEPSTRUCT; /* histogram */
+#endif
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ png_byte heuristic_method PNG_DEPSTRUCT; /* heuristic for row
+ filter selection */
+ png_byte num_prev_filters PNG_DEPSTRUCT; /* number of weights
+ for previous rows */
+ png_bytep prev_filters PNG_DEPSTRUCT; /* filter type(s) of
+ previous row(s) */
+ png_uint_16p filter_weights PNG_DEPSTRUCT; /* weight(s) for previous
+ line(s) */
+ png_uint_16p inv_filter_weights PNG_DEPSTRUCT; /* 1/weight(s) for
+ previous line(s) */
+ png_uint_16p filter_costs PNG_DEPSTRUCT; /* relative filter
+ calculation cost */
+ png_uint_16p inv_filter_costs PNG_DEPSTRUCT; /* 1/relative filter
+ calculation cost */
+#endif
+
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+ png_charp time_buffer PNG_DEPSTRUCT; /* String to hold RFC 1123 time text */
+#endif
+
+/* New members added in libpng-1.0.6 */
+
+ png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is
+ responsible for freeing */
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+ png_voidp user_chunk_ptr PNG_DEPSTRUCT;
+ png_user_chunk_ptr read_user_chunk_fn PNG_DEPSTRUCT; /* user read
+ chunk handler */
+#endif
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ int num_chunk_list PNG_DEPSTRUCT;
+ png_bytep chunk_list PNG_DEPSTRUCT;
+#endif
+
+/* New members added in libpng-1.0.3 */
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ png_byte rgb_to_gray_status PNG_DEPSTRUCT;
+ /* These were changed from png_byte in libpng-1.0.6 */
+ png_uint_16 rgb_to_gray_red_coeff PNG_DEPSTRUCT;
+ png_uint_16 rgb_to_gray_green_coeff PNG_DEPSTRUCT;
+ png_uint_16 rgb_to_gray_blue_coeff PNG_DEPSTRUCT;
+#endif
+
+/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
+#if defined(PNG_MNG_FEATURES_SUPPORTED) || \
+ defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
+ defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
+/* Changed from png_byte to png_uint_32 at version 1.2.0 */
+ png_uint_32 mng_features_permitted PNG_DEPSTRUCT;
+#endif
+
+/* New member added in libpng-1.0.7 */
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ png_fixed_point int_gamma PNG_DEPSTRUCT;
+#endif
+
+/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ png_byte filter_type PNG_DEPSTRUCT;
+#endif
+
+/* New members added in libpng-1.2.0 */
+
+/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_voidp mem_ptr PNG_DEPSTRUCT; /* user supplied struct for
+ mem functions */
+ png_malloc_ptr malloc_fn PNG_DEPSTRUCT; /* function for
+ allocating memory */
+ png_free_ptr free_fn PNG_DEPSTRUCT; /* function for
+ freeing memory */
+#endif
+
+/* New member added in libpng-1.0.13 and 1.2.0 */
+ png_bytep big_row_buf PNG_DEPSTRUCT; /* buffer to save current
+ (unfiltered) row */
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* The following three members were added at version 1.0.14 and 1.2.4 */
+ png_bytep quantize_sort PNG_DEPSTRUCT; /* working sort array */
+ png_bytep index_to_palette PNG_DEPSTRUCT; /* where the original
+ index currently is
+ in the palette */
+ png_bytep palette_to_index PNG_DEPSTRUCT; /* which original index
+ points to this
+ palette color */
+#endif
+
+/* New members added in libpng-1.0.16 and 1.2.6 */
+ png_byte compression_type PNG_DEPSTRUCT;
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ png_uint_32 user_width_max PNG_DEPSTRUCT;
+ png_uint_32 user_height_max PNG_DEPSTRUCT;
+ /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
+ * chunks that can be stored (0 means unlimited).
+ */
+ png_uint_32 user_chunk_cache_max PNG_DEPSTRUCT;
+#endif
+
+/* New member added in libpng-1.0.25 and 1.2.17 */
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+ /* Storage for unknown chunk that the library doesn't recognize. */
+ png_unknown_chunk unknown_chunk PNG_DEPSTRUCT;
+#endif
+
+/* New members added in libpng-1.2.26 */
+ png_uint_32 old_big_row_buf_size PNG_DEPSTRUCT;
+ png_uint_32 old_prev_row_size PNG_DEPSTRUCT;
+
+/* New member added in libpng-1.2.30 */
+ png_charp chunkdata PNG_DEPSTRUCT; /* buffer for reading chunk data */
+
+#ifdef PNG_IO_STATE_SUPPORTED
+/* New member added in libpng-1.4.0 */
+ png_uint_32 io_state PNG_DEPSTRUCT;
+#endif
+};
+
+
+/* This triggers a compiler error in png.c, if png.c and png.h
+ * do not agree upon the version number.
+ */
+typedef png_structp version_1_4_4;
+
+typedef png_struct FAR * FAR * png_structpp;
+
+/* Here are the function definitions most commonly used. This is not
+ * the place to find out how to use libpng. See libpng.txt for the
+ * full explanation, see example.c for the summary. This just provides
+ * a simple one line description of the use of each function.
+ */
+
+/* Returns the version number of the library */
+PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
+
+/* Tell lib we have already handled the first <num_bytes> magic bytes.
+ * Handling more than 8 bytes from the beginning of the file is an error.
+ */
+PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
+ int num_bytes));
+
+/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
+ * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
+ * signature, and non-zero otherwise. Having num_to_check == 0 or
+ * start > 7 will always fail (ie return non-zero).
+ */
+PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
+ png_size_t num_to_check));
+
+/* Simple signature checking function. This is the same as calling
+ * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
+ */
+#define png_check_sig(sig,n) !png_sig_cmp((sig), 0, (n))
+
+/* Allocate and initialize png_ptr struct for reading, and any other memory. */
+PNG_EXPORT(png_structp,png_create_read_struct)
+ PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
+
+/* Allocate and initialize png_ptr struct for writing, and any other memory */
+PNG_EXPORT(png_structp,png_create_write_struct)
+ PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
+
+PNG_EXPORT(png_size_t,png_get_compression_buffer_size)
+ PNGARG((png_structp png_ptr));
+
+PNG_EXPORT(void,png_set_compression_buffer_size)
+ PNGARG((png_structp png_ptr, png_size_t size));
+
+/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
+ * match up.
+ */
+#ifdef PNG_SETJMP_SUPPORTED
+/* This function returns the jmp_buf built in to *png_ptr. It must be
+ * supplied with an appropriate 'longjmp' function to use on that jmp_buf
+ * unless the default error function is overridden in which case NULL is
+ * acceptable. The size of the jmp_buf is checked against the actual size
+ * allocated by the library - the call will return NULL on a mismatch
+ * indicating an ABI mismatch.
+ */
+PNG_EXPORT(jmp_buf*, png_set_longjmp_fn)
+ PNGARG((png_structp png_ptr, png_longjmp_ptr longjmp_fn, size_t
+ jmp_buf_size));
+# define png_jmpbuf(png_ptr) \
+ (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
+#else
+# define png_jmpbuf(png_ptr) \
+ (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
+#endif
+
+#ifdef PNG_READ_SUPPORTED
+/* Reset the compression stream */
+PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
+#endif
+
+/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_EXPORT(png_structp,png_create_read_struct_2)
+ PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
+PNG_EXPORT(png_structp,png_create_write_struct_2)
+ PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
+#endif
+
+/* Write the PNG file signature. */
+PNG_EXPORT(void,png_write_sig) PNGARG((png_structp png_ptr));
+
+/* Write a PNG chunk - size, type, (optional) data, CRC. */
+PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
+ png_bytep chunk_name, png_bytep data, png_size_t length));
+
+/* Write the start of a PNG chunk - length and chunk name. */
+PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
+ png_bytep chunk_name, png_uint_32 length));
+
+/* Write the data of a PNG chunk started with png_write_chunk_start(). */
+PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
+ png_bytep data, png_size_t length));
+
+/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
+PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
+
+/* Allocate and initialize the info structure */
+PNG_EXPORT(png_infop,png_create_info_struct)
+ PNGARG((png_structp png_ptr)) PNG_ALLOCATED;
+
+PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
+ png_size_t png_info_struct_size));
+
+/* Writes all the PNG information before the image. */
+PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the information before the actual image data. */
+PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+#endif
+
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+PNG_EXPORT(png_charp,png_convert_to_rfc1123)
+ PNGARG((png_structp png_ptr, png_timep ptime));
+#endif
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+/* Convert from a struct tm to png_time */
+PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
+ struct tm FAR * ttime));
+
+/* Convert from time_t to png_time. Uses gmtime() */
+PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
+ time_t ttime));
+#endif /* PNG_CONVERT_tIME_SUPPORTED */
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
+PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
+PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
+ png_ptr));
+PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
+PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Use blue, green, red order for pixels. */
+PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+/* Expand the grayscale to 24-bit RGB if necessary. */
+PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* Reduce RGB to grayscale. */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
+ int error_action, double red, double green ));
+#endif
+PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
+ int error_action, png_fixed_point red, png_fixed_point green ));
+PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
+ png_ptr));
+#endif
+
+PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
+ png_colorp palette));
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
+PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
+ png_uint_32 filler, int flags));
+/* The values of the PNG_FILLER_ defines should NOT be changed */
+#define PNG_FILLER_BEFORE 0
+#define PNG_FILLER_AFTER 1
+/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
+PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
+ png_uint_32 filler, int flags));
+#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Swap bytes in 16-bit depth files. */
+PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
+PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
+ defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* Swap packing order of pixels in bytes. */
+PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+/* Converts files to legal bit depths. */
+PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
+ png_color_8p true_bits));
+#endif
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+ defined(PNG_WRITE_INTERLACING_SUPPORTED)
+/* Have the code handle the interlacing. Returns the number of passes. */
+PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+/* Invert monochrome files */
+PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
+#endif
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+/* Handle alpha and tRNS by replacing with a background color. */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
+ png_color_16p background_color, int background_gamma_code,
+ int need_expand, double background_gamma));
+#endif
+#define PNG_BACKGROUND_GAMMA_UNKNOWN 0
+#define PNG_BACKGROUND_GAMMA_SCREEN 1
+#define PNG_BACKGROUND_GAMMA_FILE 2
+#define PNG_BACKGROUND_GAMMA_UNIQUE 3
+#endif
+
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+/* Strip the second byte of information from a 16-bit depth file. */
+PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Turn on quantizing, and reduce the palette to the number of colors
+ * available. Prior to libpng-1.4.2, this was png_set_dither().
+ */
+PNG_EXPORT(void,png_set_quantize) PNGARG((png_structp png_ptr,
+ png_colorp palette, int num_palette, int maximum_colors,
+ png_uint_16p histogram, int full_quantize));
+#endif
+/* This migration aid will be removed from libpng-1.5.0 */
+#define png_set_dither png_set_quantize
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* Handle gamma correction. Screen_gamma=(display_exponent) */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
+ double screen_gamma, double default_file_gamma));
+#endif
+#endif
+
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+/* Set how many lines between output flushes - 0 for no flushing */
+PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
+/* Flush the current PNG output buffer */
+PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
+#endif
+
+/* Optional update palette with requested transformations */
+PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
+
+/* Optional call to update the users info structure */
+PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read one or more rows of image data. */
+PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
+ png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
+#endif
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read a row of data. */
+PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
+ png_bytep row,
+ png_bytep display_row));
+#endif
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the whole image into memory at once. */
+PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
+ png_bytepp image));
+#endif
+
+/* Write a row of image data */
+PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
+ png_bytep row));
+
+/* Write a few rows of image data */
+PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
+ png_bytepp row, png_uint_32 num_rows));
+
+/* Write the image data */
+PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
+ png_bytepp image));
+
+/* Write the end of the PNG file. */
+PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the end of the PNG file. */
+PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+#endif
+
+/* Free any memory associated with the png_info_struct */
+PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
+ png_infopp info_ptr_ptr));
+
+/* Free any memory associated with the png_struct and the png_info_structs */
+PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
+ png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
+
+/* Free any memory associated with the png_struct and the png_info_structs */
+PNG_EXPORT(void,png_destroy_write_struct)
+ PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
+
+/* Set the libpng method of handling chunk CRC errors */
+PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
+ int crit_action, int ancil_action));
+
+/* Values for png_set_crc_action() to say how to handle CRC errors in
+ * ancillary and critical chunks, and whether to use the data contained
+ * therein. Note that it is impossible to "discard" data in a critical
+ * chunk. For versions prior to 0.90, the action was always error/quit,
+ * whereas in version 0.90 and later, the action for CRC errors in ancillary
+ * chunks is warn/discard. These values should NOT be changed.
+ *
+ * value action:critical action:ancillary
+ */
+#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
+#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
+#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
+#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
+#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
+#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
+
+/* These functions give the user control over the scan-line filtering in
+ * libpng and the compression methods used by zlib. These functions are
+ * mainly useful for testing, as the defaults should work with most users.
+ * Those users who are tight on memory or want faster performance at the
+ * expense of compression can modify them. See the compression library
+ * header file (zlib.h) for an explination of the compression functions.
+ */
+
+/* Set the filtering method(s) used by libpng. Currently, the only valid
+ * value for "method" is 0.
+ */
+PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
+ int filters));
+
+/* Flags for png_set_filter() to say which filters to use. The flags
+ * are chosen so that they don't conflict with real filter types
+ * below, in case they are supplied instead of the #defined constants.
+ * These values should NOT be changed.
+ */
+#define PNG_NO_FILTERS 0x00
+#define PNG_FILTER_NONE 0x08
+#define PNG_FILTER_SUB 0x10
+#define PNG_FILTER_UP 0x20
+#define PNG_FILTER_AVG 0x40
+#define PNG_FILTER_PAETH 0x80
+#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
+ PNG_FILTER_AVG | PNG_FILTER_PAETH)
+
+/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
+ * These defines should NOT be changed.
+ */
+#define PNG_FILTER_VALUE_NONE 0
+#define PNG_FILTER_VALUE_SUB 1
+#define PNG_FILTER_VALUE_UP 2
+#define PNG_FILTER_VALUE_AVG 3
+#define PNG_FILTER_VALUE_PAETH 4
+#define PNG_FILTER_VALUE_LAST 5
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
+/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
+ * defines, either the default (minimum-sum-of-absolute-differences), or
+ * the experimental method (weighted-minimum-sum-of-absolute-differences).
+ *
+ * Weights are factors >= 1.0, indicating how important it is to keep the
+ * filter type consistent between rows. Larger numbers mean the current
+ * filter is that many times as likely to be the same as the "num_weights"
+ * previous filters. This is cumulative for each previous row with a weight.
+ * There needs to be "num_weights" values in "filter_weights", or it can be
+ * NULL if the weights aren't being specified. Weights have no influence on
+ * the selection of the first row filter. Well chosen weights can (in theory)
+ * improve the compression for a given image.
+ *
+ * Costs are factors >= 1.0 indicating the relative decoding costs of a
+ * filter type. Higher costs indicate more decoding expense, and are
+ * therefore less likely to be selected over a filter with lower computational
+ * costs. There needs to be a value in "filter_costs" for each valid filter
+ * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
+ * setting the costs. Costs try to improve the speed of decompression without
+ * unduly increasing the compressed image size.
+ *
+ * A negative weight or cost indicates the default value is to be used, and
+ * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
+ * The default values for both weights and costs are currently 1.0, but may
+ * change if good general weighting/cost heuristics can be found. If both
+ * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
+ * to the UNWEIGHTED method, but with added encoding time/computation.
+ */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
+ int heuristic_method, int num_weights, png_doublep filter_weights,
+ png_doublep filter_costs));
+#endif
+#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+
+/* Heuristic used for row filter selection. These defines should NOT be
+ * changed.
+ */
+#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
+#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
+#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
+#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
+
+/* Set the library compression level. Currently, valid values range from
+ * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
+ * (0 - no compression, 9 - "maximal" compression). Note that tests have
+ * shown that zlib compression levels 3-6 usually perform as well as level 9
+ * for PNG images, and do considerably fewer caclulations. In the future,
+ * these values may not correspond directly to the zlib compression levels.
+ */
+PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
+ int level));
+
+PNG_EXPORT(void,png_set_compression_mem_level)
+ PNGARG((png_structp png_ptr, int mem_level));
+
+PNG_EXPORT(void,png_set_compression_strategy)
+ PNGARG((png_structp png_ptr, int strategy));
+
+PNG_EXPORT(void,png_set_compression_window_bits)
+ PNGARG((png_structp png_ptr, int window_bits));
+
+PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
+ int method));
+
+/* These next functions are called for input/output, memory, and error
+ * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
+ * and call standard C I/O routines such as fread(), fwrite(), and
+ * fprintf(). These functions can be made to use other I/O routines
+ * at run time for those applications that need to handle I/O in a
+ * different manner by calling png_set_???_fn(). See libpng.txt for
+ * more information.
+ */
+
+#ifdef PNG_STDIO_SUPPORTED
+/* Initialize the input/output for the PNG file to the default functions. */
+PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr,
+ png_FILE_p fp));
+#endif
+
+/* Replace the (error and abort), and warning functions with user
+ * supplied functions. If no messages are to be printed you must still
+ * write and use replacement functions. The replacement error_fn should
+ * still do a longjmp to the last setjmp location if you are using this
+ * method of error handling. If error_fn or warning_fn is NULL, the
+ * default function will be used.
+ */
+
+PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
+ png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
+
+/* Return the user pointer associated with the error functions */
+PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
+
+/* Replace the default data output functions with a user supplied one(s).
+ * If buffered output is not used, then output_flush_fn can be set to NULL.
+ * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
+ * output_flush_fn will be ignored (and thus can be NULL).
+ * It is probably a mistake to use NULL for output_flush_fn if
+ * write_data_fn is not also NULL unless you have built libpng with
+ * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
+ * default flush function, which uses the standard *FILE structure, will
+ * be used.
+ */
+PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
+ png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
+
+/* Replace the default data input function with a user supplied one. */
+PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
+ png_voidp io_ptr, png_rw_ptr read_data_fn));
+
+/* Return the user pointer associated with the I/O functions */
+PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
+
+PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
+ png_read_status_ptr read_row_fn));
+
+PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
+ png_write_status_ptr write_row_fn));
+
+#ifdef PNG_USER_MEM_SUPPORTED
+/* Replace the default memory allocation functions with user supplied one(s). */
+PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
+ png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
+/* Return the user pointer associated with the memory functions */
+PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
+#endif
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
+ png_ptr, png_user_transform_ptr read_user_transform_fn));
+#endif
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
+ png_ptr, png_user_transform_ptr write_user_transform_fn));
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
+ png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
+ int user_transform_channels));
+/* Return the user pointer associated with the user transform functions */
+PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
+ PNGARG((png_structp png_ptr));
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
+ png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
+PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
+ png_ptr));
+#endif
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+/* Sets the function callbacks for the push reader, and a pointer to a
+ * user-defined structure available to the callback functions.
+ */
+PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
+ png_voidp progressive_ptr,
+ png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
+ png_progressive_end_ptr end_fn));
+
+/* Returns the user pointer associated with the push read functions */
+PNG_EXPORT(png_voidp,png_get_progressive_ptr)
+ PNGARG((png_structp png_ptr));
+
+/* Function to be called when data becomes available */
+PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
+
+/* Function that combines rows. Not very much different than the
+ * png_combine_row() call. Is this even used?????
+ */
+PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
+ png_bytep old_row, png_bytep new_row));
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+
+PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
+ png_alloc_size_t size)) PNG_ALLOCATED;
+/* Added at libpng version 1.4.0 */
+PNG_EXPORT(png_voidp,png_calloc) PNGARG((png_structp png_ptr,
+ png_alloc_size_t size)) PNG_ALLOCATED;
+
+/* Added at libpng version 1.2.4 */
+PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
+ png_alloc_size_t size)) PNG_ALLOCATED;
+
+/* Frees a pointer allocated by png_malloc() */
+PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
+
+/* Free data that was allocated internally */
+PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 free_me, int num));
+/* Reassign responsibility for freeing existing data, whether allocated
+ * by libpng or by the application */
+PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int freer, png_uint_32 mask));
+/* Assignments for png_data_freer */
+#define PNG_DESTROY_WILL_FREE_DATA 1
+#define PNG_SET_WILL_FREE_DATA 1
+#define PNG_USER_WILL_FREE_DATA 2
+/* Flags for png_ptr->free_me and info_ptr->free_me */
+#define PNG_FREE_HIST 0x0008
+#define PNG_FREE_ICCP 0x0010
+#define PNG_FREE_SPLT 0x0020
+#define PNG_FREE_ROWS 0x0040
+#define PNG_FREE_PCAL 0x0080
+#define PNG_FREE_SCAL 0x0100
+#define PNG_FREE_UNKN 0x0200
+#define PNG_FREE_LIST 0x0400
+#define PNG_FREE_PLTE 0x1000
+#define PNG_FREE_TRNS 0x2000
+#define PNG_FREE_TEXT 0x4000
+#define PNG_FREE_ALL 0x7fff
+#define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
+
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
+ png_alloc_size_t size)) PNG_ALLOCATED;
+PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
+ png_voidp ptr));
+#endif
+
+#ifndef PNG_NO_ERROR_TEXT
+/* Fatal error in PNG image of libpng - can't continue */
+PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
+ png_const_charp error_message)) PNG_NORETURN;
+
+/* The same, but the chunk name is prepended to the error string. */
+PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
+ png_const_charp error_message)) PNG_NORETURN;
+
+#else
+/* Fatal error in PNG image of libpng - can't continue */
+PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr)) PNG_NORETURN;
+#endif
+
+/* Non-fatal error in libpng. Can continue, but may have a problem. */
+PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
+ png_const_charp warning_message));
+
+/* Non-fatal error in libpng, chunk name is prepended to message. */
+PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
+ png_const_charp warning_message));
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+/* Benign error in libpng. Can continue, but may have a problem.
+ * User can choose whether to handle as a fatal error or as a warning. */
+PNG_EXPORT(void,png_benign_error) PNGARG((png_structp png_ptr,
+ png_const_charp warning_message));
+
+/* Same, chunk name is prepended to message. */
+PNG_EXPORT(void,png_chunk_benign_error) PNGARG((png_structp png_ptr,
+ png_const_charp warning_message));
+
+PNG_EXPORT(void,png_set_benign_errors) PNGARG((png_structp
+ png_ptr, int allowed));
+#endif
+
+/* The png_set_<chunk> functions are for storing values in the png_info_struct.
+ * Similarly, the png_get_<chunk> calls are used to read values from the
+ * png_info_struct, either storing the parameters in the passed variables, or
+ * setting pointers into the png_info_struct where the data is stored. The
+ * png_get_<chunk> functions return a non-zero value if the data was available
+ * in info_ptr, or return zero and do not change any of the parameters if the
+ * data was not available.
+ *
+ * These functions should be used instead of directly accessing png_info
+ * to avoid problems with future changes in the size and internal layout of
+ * png_info_struct.
+ */
+/* Returns "flag" if chunk data is valid in info_ptr. */
+PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
+png_infop info_ptr, png_uint_32 flag));
+
+/* Returns number of bytes needed to hold a transformed row. */
+PNG_EXPORT(png_size_t,png_get_rowbytes) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+/* Returns row_pointers, which is an array of pointers to scanlines that was
+ * returned from png_read_png().
+ */
+PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+/* Set row_pointers, which is an array of pointers to scanlines for use
+ * by png_write_png().
+ */
+PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_bytepp row_pointers));
+#endif
+
+/* Returns number of color channels in image. */
+PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* Returns image width in pixels. */
+PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image height in pixels. */
+PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image bit_depth. */
+PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image color_type. */
+PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image filter_type. */
+PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image interlace_type. */
+PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image compression_type. */
+PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image resolution in pixels per meter, from pHYs chunk data. */
+PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns pixel aspect ratio, computed from pHYs chunk data. */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+#endif
+
+/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
+PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+#endif /* PNG_EASY_ACCESS_SUPPORTED */
+
+/* Returns pointer to signature string read from PNG header */
+PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+
+#ifdef PNG_bKGD_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_color_16p *background));
+#endif
+
+#ifdef PNG_bKGD_SUPPORTED
+PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_color_16p background));
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, double *white_x, double *white_y, double *red_x,
+ double *red_y, double *green_x, double *green_y, double *blue_x,
+ double *blue_y));
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
+ *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
+ png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
+ *int_blue_x, png_fixed_point *int_blue_y));
+#endif
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, double white_x, double white_y, double red_x,
+ double red_y, double green_x, double green_y, double blue_x, double blue_y));
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
+ png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
+ int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
+ png_fixed_point int_blue_y));
+#endif
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, double *file_gamma));
+#endif
+PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_fixed_point *int_file_gamma));
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, double file_gamma));
+#endif
+PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_fixed_point int_file_gamma));
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_16p *hist));
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_16p hist));
+#endif
+
+PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
+ int *bit_depth, int *color_type, int *interlace_method,
+ int *compression_method, int *filter_method));
+
+PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_method, int compression_method,
+ int filter_method));
+
+#ifdef PNG_oFFs_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
+ int *unit_type));
+#endif
+
+#ifdef PNG_oFFs_SUPPORTED
+PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
+ int unit_type));
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
+ int *type, int *nparams, png_charp *units, png_charpp *params));
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
+ int type, int nparams, png_charp units, png_charpp params));
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
+#endif
+
+PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_colorp *palette, int *num_palette));
+
+PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_colorp palette, int num_palette));
+
+#ifdef PNG_sBIT_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_color_8p *sig_bit));
+#endif
+
+#ifdef PNG_sBIT_SUPPORTED
+PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_color_8p sig_bit));
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int *intent));
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int intent));
+PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int intent));
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_charpp name, int *compression_type,
+ png_charpp profile, png_uint_32 *proflen));
+ /* Note to maintainer: profile should be png_bytepp */
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_charp name, int compression_type,
+ png_charp profile, png_uint_32 proflen));
+ /* Note to maintainer: profile should be png_bytep */
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_sPLT_tpp entries));
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_sPLT_tp entries, int nentries));
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+/* png_get_text also returns the number of text chunks in *num_text */
+PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_textp *text_ptr, int *num_text));
+#endif
+
+/* Note while png_set_text() will accept a structure whose text,
+ * language, and translated keywords are NULL pointers, the structure
+ * returned by png_get_text will always contain regular
+ * zero-terminated C strings. They might be empty strings but
+ * they will never be NULL pointers.
+ */
+
+#ifdef PNG_TEXT_SUPPORTED
+PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_textp text_ptr, int num_text));
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_timep *mod_time));
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_timep mod_time));
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_bytep *trans_alpha, int *num_trans,
+ png_color_16p *trans_color));
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_bytep trans_alpha, int num_trans,
+ png_color_16p trans_color));
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int *unit, double *width, double *height));
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
+#endif
+#endif
+#endif /* PNG_sCAL_SUPPORTED */
+
+#ifdef PNG_sCAL_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int unit, double width, double height));
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
+#endif
+#endif
+#endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+/* Provide a list of chunks and how they are to be handled, if the built-in
+ handling or default unknown chunk handling is not desired. Any chunks not
+ listed will be handled in the default manner. The IHDR and IEND chunks
+ must not be listed.
+ keep = 0: follow default behaviour
+ = 1: do not keep
+ = 2: keep only if safe-to-copy
+ = 3: keep even if unsafe-to-copy
+*/
+PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
+ png_ptr, int keep, png_bytep chunk_list, int num_chunks));
+PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
+ chunk_name));
+#endif
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
+PNG_EXPORT(void, png_set_unknown_chunk_location)
+ PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
+PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
+ png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
+#endif
+
+/* Png_free_data() will turn off the "valid" flag for anything it frees.
+ * If you need to turn it off for a chunk that your application has freed,
+ * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
+ */
+PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int mask));
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+/* The "params" pointer is currently not used and is for future expansion. */
+PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
+ png_infop info_ptr,
+ int transforms,
+ png_voidp params));
+PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
+ png_infop info_ptr,
+ int transforms,
+ png_voidp params));
+#endif
+
+PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
+PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
+PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp
+ png_ptr));
+PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
+ png_ptr, png_uint_32 mng_features_permitted));
+#endif
+
+/* For use in png_set_keep_unknown, added to version 1.2.6 */
+#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
+#define PNG_HANDLE_CHUNK_NEVER 1
+#define PNG_HANDLE_CHUNK_IF_SAFE 2
+#define PNG_HANDLE_CHUNK_ALWAYS 3
+
+/* Strip the prepended error numbers ("#nnn ") from error and warning
+ * messages before passing them to the error or warning handler.
+ */
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
+ png_ptr, png_uint_32 strip_mode));
+#endif
+
+/* Added in libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
+ png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
+PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
+ png_ptr));
+PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
+ png_ptr));
+/* Added in libpng-1.4.0 */
+PNG_EXPORT(void,png_set_chunk_cache_max) PNGARG((png_structp
+ png_ptr, png_uint_32 user_chunk_cache_max));
+PNG_EXPORT(png_uint_32,png_get_chunk_cache_max)
+ PNGARG((png_structp png_ptr));
+/* Added in libpng-1.4.1 */
+PNG_EXPORT(void,png_set_chunk_malloc_max) PNGARG((png_structp
+ png_ptr, png_alloc_size_t user_chunk_cache_max));
+PNG_EXPORT(png_alloc_size_t,png_get_chunk_malloc_max)
+ PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
+PNG_EXPORT(png_uint_32,png_get_pixels_per_inch) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+
+PNG_EXPORT(png_uint_32,png_get_x_pixels_per_inch) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+
+PNG_EXPORT(png_uint_32,png_get_y_pixels_per_inch) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+
+PNG_EXPORT(float,png_get_x_offset_inches) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+
+PNG_EXPORT(float,png_get_y_offset_inches) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+
+#ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_pHYs_dpi) PNGARG((png_structp png_ptr,
+png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
+#endif /* PNG_pHYs_SUPPORTED */
+#endif /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
+
+/* Added in libpng-1.4.0 */
+#ifdef PNG_IO_STATE_SUPPORTED
+PNG_EXPORT(png_uint_32,png_get_io_state) PNGARG((png_structp png_ptr));
+
+PNG_EXPORT(png_bytep,png_get_io_chunk_name)
+ PNGARG((png_structp png_ptr));
+
+/* The flags returned by png_get_io_state() are the following: */
+#define PNG_IO_NONE 0x0000 /* no I/O at this moment */
+#define PNG_IO_READING 0x0001 /* currently reading */
+#define PNG_IO_WRITING 0x0002 /* currently writing */
+#define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
+#define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
+#define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
+#define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
+#define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
+#define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
+#endif /* ?PNG_IO_STATE_SUPPORTED */
+
+/* Maintainer: Put new public prototypes here ^, in libpng.3, and project
+ * defs
+ */
+
+#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
+/* With these routines we avoid an integer divide, which will be slower on
+ * most machines. However, it does take more operations than the corresponding
+ * divide method, so it may be slower on a few RISC systems. There are two
+ * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
+ *
+ * Note that the rounding factors are NOT supposed to be the same! 128 and
+ * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
+ * standard method.
+ *
+ * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
+ */
+
+ /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
+
+# define png_composite(composite, fg, alpha, bg) \
+ { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
+ * (png_uint_16)(alpha) \
+ + (png_uint_16)(bg)*(png_uint_16)(255 \
+ - (png_uint_16)(alpha)) + (png_uint_16)128); \
+ (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
+
+# define png_composite_16(composite, fg, alpha, bg) \
+ { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
+ * (png_uint_32)(alpha) \
+ + (png_uint_32)(bg)*(png_uint_32)(65535L \
+ - (png_uint_32)(alpha)) + (png_uint_32)32768L); \
+ (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
+
+#else /* Standard method using integer division */
+
+# define png_composite(composite, fg, alpha, bg) \
+ (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
+ (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
+ (png_uint_16)127) / 255)
+
+# define png_composite_16(composite, fg, alpha, bg) \
+ (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
+ (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
+ (png_uint_32)32767) / (png_uint_32)65535L)
+#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
+
+#ifdef PNG_USE_READ_MACROS
+/* Inline macros to do direct reads of bytes from the input buffer.
+ * The png_get_int_32() routine assumes we are using two's complement
+ * format for negative values, which is almost certainly true.
+ */
+# define png_get_uint_32(buf) \
+ (((png_uint_32)(*(buf)) << 24) + \
+ ((png_uint_32)(*((buf) + 1)) << 16) + \
+ ((png_uint_32)(*((buf) + 2)) << 8) + \
+ ((png_uint_32)(*((buf) + 3))))
+# define png_get_uint_16(buf) \
+ (((png_uint_32)(*(buf)) << 8) + \
+ ((png_uint_32)(*((buf) + 1))))
+# define png_get_int_32(buf) \
+ ((png_int_32)((*(buf) & 0x80) \
+ ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffff)+1)) \
+ : (png_int_32)png_get_uint_32(buf)))
+#else
+PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
+PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
+#ifdef PNG_GET_INT_32_SUPPORTED
+PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
+#endif
+#endif
+PNG_EXPORT(png_uint_32,png_get_uint_31)
+ PNGARG((png_structp png_ptr, png_bytep buf));
+/* No png_get_int_16 -- may be added if there's a real need for it. */
+
+/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
+PNG_EXPORT(void,png_save_uint_32)
+ PNGARG((png_bytep buf, png_uint_32 i));
+PNG_EXPORT(void,png_save_int_32)
+ PNGARG((png_bytep buf, png_int_32 i));
+
+/* Place a 16-bit number into a buffer in PNG byte order.
+ * The parameter is declared unsigned int, not png_uint_16,
+ * just to avoid potential problems on pre-ANSI C compilers.
+ */
+PNG_EXPORT(void,png_save_uint_16)
+ PNGARG((png_bytep buf, unsigned int i));
+/* No png_save_int_16 -- may be added if there's a real need for it. */
+
+/* ************************************************************************* */
+
+/* Various modes of operation. Note that after an init, mode is set to
+ * zero automatically when the structure is created.
+ */
+#define PNG_HAVE_IHDR 0x01
+#define PNG_HAVE_PLTE 0x02
+#define PNG_HAVE_IDAT 0x04
+#define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
+#define PNG_HAVE_IEND 0x10
+#define PNG_HAVE_gAMA 0x20
+#define PNG_HAVE_cHRM 0x40
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PNG_VERSION_INFO_ONLY */
+/* Do not put anything past this line */
+#endif /* PNG_H */
--- /dev/null
+
+/* pngconf.h - machine configurable file for libpng
+ *
+ * libpng version 1.4.4 - September 23, 2010
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ */
+
+/* Any machine specific code is near the front of this file, so if you
+ * are configuring libpng for a machine, you may want to read the section
+ * starting here down to where it starts to typedef png_color, png_text,
+ * and png_info.
+ */
+
+#ifndef PNGCONF_H
+#define PNGCONF_H
+
+#ifndef PNG_NO_LIMITS_H
+# include <limits.h>
+#endif
+
+/* Added at libpng-1.2.9 */
+
+/* config.h is created by and PNG_CONFIGURE_LIBPNG is set by the "configure"
+ * script.
+ */
+#ifdef PNG_CONFIGURE_LIBPNG
+# ifdef HAVE_CONFIG_H
+# include "config.h"
+# endif
+#endif
+
+/*
+ * Added at libpng-1.2.8
+ *
+ * PNG_USER_CONFIG has to be defined on the compiler command line. This
+ * includes the resource compiler for Windows DLL configurations.
+ */
+#ifdef PNG_USER_CONFIG
+# include "pngusr.h"
+# ifndef PNG_USER_PRIVATEBUILD
+# define PNG_USER_PRIVATEBUILD
+# endif
+#endif
+
+/*
+ * If you create a private DLL you should define in "pngusr.h" the following:
+ * #define PNG_USER_PRIVATEBUILD <Describes by whom and why this version of
+ * the DLL was built>
+ * e.g. #define PNG_USER_PRIVATEBUILD "Build by MyCompany for xyz reasons."
+ * #define PNG_USER_DLLFNAME_POSTFIX <two-letter postfix that serve to
+ * distinguish your DLL from those of the official release. These
+ * correspond to the trailing letters that come after the version
+ * number and must match your private DLL name>
+ * e.g. // private DLL "libpng14gx.dll"
+ * #define PNG_USER_DLLFNAME_POSTFIX "gx"
+ *
+ * The following macros are also at your disposal if you want to complete the
+ * DLL VERSIONINFO structure.
+ * - PNG_USER_VERSIONINFO_COMMENTS
+ * - PNG_USER_VERSIONINFO_COMPANYNAME
+ * - PNG_USER_VERSIONINFO_LEGALTRADEMARKS
+ */
+
+#ifdef __STDC__
+# ifdef SPECIALBUILD
+# pragma message("PNG_LIBPNG_SPECIALBUILD (and deprecated SPECIALBUILD)\
+ are now LIBPNG reserved macros. Use PNG_USER_PRIVATEBUILD instead.")
+# endif
+
+# ifdef PRIVATEBUILD
+# pragma message("PRIVATEBUILD is deprecated.\
+ Use PNG_USER_PRIVATEBUILD instead.")
+# define PNG_USER_PRIVATEBUILD PRIVATEBUILD
+# endif
+#endif /* __STDC__ */
+
+/* End of material added to libpng-1.2.8 */
+
+#ifndef PNG_VERSION_INFO_ONLY
+
+/* This is the size of the compression buffer, and thus the size of
+ * an IDAT chunk. Make this whatever size you feel is best for your
+ * machine. One of these will be allocated per png_struct. When this
+ * is full, it writes the data to the disk, and does some other
+ * calculations. Making this an extremely small size will slow
+ * the library down, but you may want to experiment to determine
+ * where it becomes significant, if you are concerned with memory
+ * usage. Note that zlib allocates at least 32Kb also. For readers,
+ * this describes the size of the buffer available to read the data in.
+ * Unless this gets smaller than the size of a row (compressed),
+ * it should not make much difference how big this is.
+ */
+
+#ifndef PNG_ZBUF_SIZE
+# define PNG_ZBUF_SIZE 8192
+#endif
+
+/* Enable if you want a write-only libpng */
+
+#ifndef PNG_NO_READ_SUPPORTED
+# define PNG_READ_SUPPORTED
+#endif
+
+/* Enable if you want a read-only libpng */
+
+#ifndef PNG_NO_WRITE_SUPPORTED
+# define PNG_WRITE_SUPPORTED
+#endif
+
+/* Enabled in 1.4.0. */
+#ifdef PNG_ALLOW_BENIGN_ERRORS
+# define png_benign_error png_warning
+# define png_chunk_benign_error png_chunk_warning
+#else
+# ifndef PNG_BENIGN_ERRORS_SUPPORTED
+# define png_benign_error png_error
+# define png_chunk_benign_error png_chunk_error
+# endif
+#endif
+
+/* Added at libpng version 1.4.0 */
+#if !defined(PNG_NO_WARNINGS) && !defined(PNG_WARNINGS_SUPPORTED)
+# define PNG_WARNINGS_SUPPORTED
+#endif
+
+/* Added at libpng version 1.4.0 */
+#if !defined(PNG_NO_ERROR_TEXT) && !defined(PNG_ERROR_TEXT_SUPPORTED)
+# define PNG_ERROR_TEXT_SUPPORTED
+#endif
+
+/* Added at libpng version 1.4.0 */
+#if !defined(PNG_NO_CHECK_cHRM) && !defined(PNG_CHECK_cHRM_SUPPORTED)
+# define PNG_CHECK_cHRM_SUPPORTED
+#endif
+
+/* Added at libpng version 1.4.0 */
+#if !defined(PNG_NO_ALIGNED_MEMORY) && !defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+# define PNG_ALIGNED_MEMORY_SUPPORTED
+#endif
+
+/* Enabled by default in 1.2.0. You can disable this if you don't need to
+ support PNGs that are embedded in MNG datastreams */
+#ifndef PNG_NO_MNG_FEATURES
+# ifndef PNG_MNG_FEATURES_SUPPORTED
+# define PNG_MNG_FEATURES_SUPPORTED
+# endif
+#endif
+
+/* Added at libpng version 1.4.0 */
+#ifndef PNG_NO_FLOATING_POINT_SUPPORTED
+# ifndef PNG_FLOATING_POINT_SUPPORTED
+# define PNG_FLOATING_POINT_SUPPORTED
+# endif
+#endif
+
+/* Added at libpng-1.4.0beta49 for testing (this test is no longer used
+ in libpng and png_calloc() is always present)
+ */
+#define PNG_CALLOC_SUPPORTED
+
+/* If you are running on a machine where you cannot allocate more
+ * than 64K of memory at once, uncomment this. While libpng will not
+ * normally need that much memory in a chunk (unless you load up a very
+ * large file), zlib needs to know how big of a chunk it can use, and
+ * libpng thus makes sure to check any memory allocation to verify it
+ * will fit into memory.
+#define PNG_MAX_MALLOC_64K
+ */
+#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
+# define PNG_MAX_MALLOC_64K
+#endif
+
+/* Special munging to support doing things the 'cygwin' way:
+ * 'Normal' png-on-win32 defines/defaults:
+ * PNG_BUILD_DLL -- building dll
+ * PNG_USE_DLL -- building an application, linking to dll
+ * (no define) -- building static library, or building an
+ * application and linking to the static lib
+ * 'Cygwin' defines/defaults:
+ * PNG_BUILD_DLL -- (ignored) building the dll
+ * (no define) -- (ignored) building an application, linking to the dll
+ * PNG_STATIC -- (ignored) building the static lib, or building an
+ * application that links to the static lib.
+ * ALL_STATIC -- (ignored) building various static libs, or building an
+ * application that links to the static libs.
+ * Thus,
+ * a cygwin user should define either PNG_BUILD_DLL or PNG_STATIC, and
+ * this bit of #ifdefs will define the 'correct' config variables based on
+ * that. If a cygwin user *wants* to define 'PNG_USE_DLL' that's okay, but
+ * unnecessary.
+ *
+ * Also, the precedence order is:
+ * ALL_STATIC (since we can't #undef something outside our namespace)
+ * PNG_BUILD_DLL
+ * PNG_STATIC
+ * (nothing) == PNG_USE_DLL
+ *
+ * CYGWIN (2002-01-20): The preceding is now obsolete. With the advent
+ * of auto-import in binutils, we no longer need to worry about
+ * __declspec(dllexport) / __declspec(dllimport) and friends. Therefore,
+ * we don't need to worry about PNG_STATIC or ALL_STATIC when it comes
+ * to __declspec() stuff. However, we DO need to worry about
+ * PNG_BUILD_DLL and PNG_STATIC because those change some defaults
+ * such as CONSOLE_IO.
+ */
+#ifdef __CYGWIN__
+# ifdef ALL_STATIC
+# ifdef PNG_BUILD_DLL
+# undef PNG_BUILD_DLL
+# endif
+# ifdef PNG_USE_DLL
+# undef PNG_USE_DLL
+# endif
+# ifdef PNG_DLL
+# undef PNG_DLL
+# endif
+# ifndef PNG_STATIC
+# define PNG_STATIC
+# endif
+# else
+# ifdef PNG_BUILD_DLL
+# ifdef PNG_STATIC
+# undef PNG_STATIC
+# endif
+# ifdef PNG_USE_DLL
+# undef PNG_USE_DLL
+# endif
+# ifndef PNG_DLL
+# define PNG_DLL
+# endif
+# else
+# ifdef PNG_STATIC
+# ifdef PNG_USE_DLL
+# undef PNG_USE_DLL
+# endif
+# ifdef PNG_DLL
+# undef PNG_DLL
+# endif
+# else
+# ifndef PNG_USE_DLL
+# define PNG_USE_DLL
+# endif
+# ifndef PNG_DLL
+# define PNG_DLL
+# endif
+# endif
+# endif
+# endif
+#endif
+
+/* This protects us against compilers that run on a windowing system
+ * and thus don't have or would rather us not use the stdio types:
+ * stdin, stdout, and stderr. The only one currently used is stderr
+ * in png_error() and png_warning(). #defining PNG_NO_CONSOLE_IO will
+ * prevent these from being compiled and used. #defining PNG_NO_STDIO
+ * will also prevent these, plus will prevent the entire set of stdio
+ * macros and functions (FILE *, printf, etc.) from being compiled and used,
+ * unless (PNG_DEBUG > 0) has been #defined.
+ *
+ * #define PNG_NO_CONSOLE_IO
+ * #define PNG_NO_STDIO
+ */
+
+#ifdef _WIN32_WCE
+# define PNG_NO_CONSOLE_IO
+# define PNG_NO_STDIO
+# define PNG_NO_TIME_RFC1123
+# ifdef PNG_DEBUG
+# undef PNG_DEBUG
+# endif
+#endif
+
+#if !defined(PNG_NO_STDIO) && !defined(PNG_STDIO_SUPPORTED)
+# define PNG_STDIO_SUPPORTED
+#endif
+
+#ifdef PNG_BUILD_DLL
+# if !defined(PNG_CONSOLE_IO_SUPPORTED) && !defined(PNG_NO_CONSOLE_IO)
+# define PNG_NO_CONSOLE_IO
+# endif
+#endif
+
+# ifdef PNG_NO_STDIO
+# ifndef PNG_NO_CONSOLE_IO
+# define PNG_NO_CONSOLE_IO
+# endif
+# ifdef PNG_DEBUG
+# if (PNG_DEBUG > 0)
+# include <stdio.h>
+# endif
+# endif
+# else
+# include <stdio.h>
+# endif
+
+#if !(defined PNG_NO_CONSOLE_IO) && !defined(PNG_CONSOLE_IO_SUPPORTED)
+# define PNG_CONSOLE_IO_SUPPORTED
+#endif
+
+/* This macro protects us against machines that don't have function
+ * prototypes (ie K&R style headers). If your compiler does not handle
+ * function prototypes, define this macro and use the included ansi2knr.
+ * I've always been able to use _NO_PROTO as the indicator, but you may
+ * need to drag the empty declaration out in front of here, or change the
+ * ifdef to suit your own needs.
+ */
+#ifndef PNGARG
+
+#ifdef OF /* zlib prototype munger */
+# define PNGARG(arglist) OF(arglist)
+#else
+
+#ifdef _NO_PROTO
+# define PNGARG(arglist) ()
+#else
+# define PNGARG(arglist) arglist
+#endif /* _NO_PROTO */
+
+#endif /* OF */
+
+#endif /* PNGARG */
+
+/* Try to determine if we are compiling on a Mac. Note that testing for
+ * just __MWERKS__ is not good enough, because the Codewarrior is now used
+ * on non-Mac platforms.
+ */
+#ifndef MACOS
+# if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
+ defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
+# define MACOS
+# endif
+#endif
+
+/* Enough people need this for various reasons to include it here */
+#if !defined(MACOS) && !defined(RISCOS)
+# include <sys/types.h>
+#endif
+
+/* PNG_SETJMP_NOT_SUPPORTED and PNG_NO_SETJMP_SUPPORTED are deprecated. */
+#if !defined(PNG_NO_SETJMP) && \
+ !defined(PNG_SETJMP_NOT_SUPPORTED) && !defined(PNG_NO_SETJMP_SUPPORTED)
+# define PNG_SETJMP_SUPPORTED
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* This is an attempt to force a single setjmp behaviour on Linux. If
+ * the X config stuff didn't define _BSD_SOURCE we wouldn't need this.
+ *
+ * You can bypass this test if you know that your application uses exactly
+ * the same setjmp.h that was included when libpng was built. Only define
+ * PNG_SKIP_SETJMP_CHECK while building your application, prior to the
+ * application's '#include "png.h"'. Don't define PNG_SKIP_SETJMP_CHECK
+ * while building a separate libpng library for general use.
+ */
+
+# ifndef PNG_SKIP_SETJMP_CHECK
+# ifdef __linux__
+# ifdef _BSD_SOURCE
+# define PNG_SAVE_BSD_SOURCE
+# undef _BSD_SOURCE
+# endif
+# ifdef _SETJMP_H
+ /* If you encounter a compiler error here, see the explanation
+ * near the end of INSTALL.
+ */
+ __pngconf.h__ in libpng already includes setjmp.h;
+ __dont__ include it again.;
+# endif
+# endif /* __linux__ */
+# endif /* PNG_SKIP_SETJMP_CHECK */
+
+ /* Include setjmp.h for error handling */
+# include <setjmp.h>
+
+# ifdef __linux__
+# ifdef PNG_SAVE_BSD_SOURCE
+# ifdef _BSD_SOURCE
+# undef _BSD_SOURCE
+# endif
+# define _BSD_SOURCE
+# undef PNG_SAVE_BSD_SOURCE
+# endif
+# endif /* __linux__ */
+#endif /* PNG_SETJMP_SUPPORTED */
+
+#ifdef BSD
+# include <strings.h>
+#else
+# include <string.h>
+#endif
+
+/* Other defines for things like memory and the like can go here. */
+
+/* This controls how fine the quantizing gets. As this allocates
+ * a largish chunk of memory (32K), those who are not as concerned
+ * with quantizing quality can decrease some or all of these.
+ */
+
+/* Prior to libpng-1.4.2, these were PNG_DITHER_*_BITS
+ * These migration aids will be removed from libpng-1.5.0.
+ */
+#ifdef PNG_DITHER_RED_BITS
+# define PNG_QUANTIZE_RED_BITS PNG_DITHER_RED_BITS
+#endif
+#ifdef PNG_DITHER_GREEN_BITS
+# define PNG_QUANTIZE_GREEN_BITS PNG_DITHER_GREEN_BITS
+#endif
+#ifdef PNG_DITHER_BLUE_BITS
+# define PNG_QUANTIZE_BLUE_BITS PNG_DITHER_BLUE_BITS
+#endif
+
+#ifndef PNG_QUANTIZE_RED_BITS
+# define PNG_QUANTIZE_RED_BITS 5
+#endif
+#ifndef PNG_QUANTIZE_GREEN_BITS
+# define PNG_QUANTIZE_GREEN_BITS 5
+#endif
+#ifndef PNG_QUANTIZE_BLUE_BITS
+# define PNG_QUANTIZE_BLUE_BITS 5
+#endif
+
+/* This controls how fine the gamma correction becomes when you
+ * are only interested in 8 bits anyway. Increasing this value
+ * results in more memory being used, and more pow() functions
+ * being called to fill in the gamma tables. Don't set this value
+ * less then 8, and even that may not work (I haven't tested it).
+ */
+
+#ifndef PNG_MAX_GAMMA_8
+# define PNG_MAX_GAMMA_8 11
+#endif
+
+/* This controls how much a difference in gamma we can tolerate before
+ * we actually start doing gamma conversion.
+ */
+#ifndef PNG_GAMMA_THRESHOLD
+# define PNG_GAMMA_THRESHOLD 0.05
+#endif
+
+/* The following uses const char * instead of char * for error
+ * and warning message functions, so some compilers won't complain.
+ * If you do not want to use const, define PNG_NO_CONST.
+ */
+
+#ifndef PNG_CONST
+# ifndef PNG_NO_CONST
+# define PNG_CONST const
+# else
+# define PNG_CONST
+# endif
+#endif
+
+/* The following defines give you the ability to remove code from the
+ * library that you will not be using. I wish I could figure out how to
+ * automate this, but I can't do that without making it seriously hard
+ * on the users. So if you are not using an ability, change the #define
+ * to an #undef, or pass in PNG_NO_feature and that part of the library
+ * will not be compiled.
+
+ * If your linker can't find a function, you may want to make sure the
+ * ability is defined here. Some of these depend upon some others being
+ * defined. I haven't figured out all the interactions here, so you may
+ * have to experiment awhile to get everything to compile. If you are
+ * creating or using a shared library, you probably shouldn't touch this,
+ * as it will affect the size of the structures, and this will cause bad
+ * things to happen if the library and/or application ever change.
+ */
+
+/* Any features you will not be using can be undef'ed here */
+
+/* GR-P, 0.96a: Set "*TRANSFORMS_SUPPORTED as default but allow user
+ * to turn it off with PNG_NO_READ|WRITE_TRANSFORMS on the compile line,
+ * then pick and choose which ones to define without having to edit this
+ * file. It is safe to use the PNG_NO_READ|WRITE_TRANSFORMS
+ * if you only want to have a png-compliant reader/writer but don't need
+ * any of the extra transformations. This saves about 80 kbytes in a
+ * typical installation of the library. (PNG_NO_* form added in version
+ * 1.0.1c, for consistency; PNG_*_TRANSFORMS_NOT_SUPPORTED deprecated in
+ * 1.4.0)
+ */
+
+/* Ignore attempt to turn off both floating and fixed point support */
+#if !defined(PNG_FLOATING_POINT_SUPPORTED) || \
+ !defined(PNG_NO_FIXED_POINT_SUPPORTED)
+# define PNG_FIXED_POINT_SUPPORTED
+#endif
+
+#ifdef PNG_READ_SUPPORTED
+
+/* PNG_READ_TRANSFORMS_NOT_SUPPORTED is deprecated. */
+#if !defined(PNG_READ_TRANSFORMS_NOT_SUPPORTED) && \
+ !defined(PNG_NO_READ_TRANSFORMS)
+# define PNG_READ_TRANSFORMS_SUPPORTED
+#endif
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+# ifndef PNG_NO_READ_EXPAND
+# define PNG_READ_EXPAND_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_SHIFT
+# define PNG_READ_SHIFT_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_PACK
+# define PNG_READ_PACK_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_BGR
+# define PNG_READ_BGR_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_SWAP
+# define PNG_READ_SWAP_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_PACKSWAP
+# define PNG_READ_PACKSWAP_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_INVERT
+# define PNG_READ_INVERT_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_QUANTIZE
+ /* Prior to libpng-1.4.0 this was PNG_READ_DITHER_SUPPORTED */
+# ifndef PNG_NO_READ_DITHER /* This migration aid will be removed */
+# define PNG_READ_QUANTIZE_SUPPORTED
+# endif
+# endif
+# ifndef PNG_NO_READ_BACKGROUND
+# define PNG_READ_BACKGROUND_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_16_TO_8
+# define PNG_READ_16_TO_8_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_FILLER
+# define PNG_READ_FILLER_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_GAMMA
+# define PNG_READ_GAMMA_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_GRAY_TO_RGB
+# define PNG_READ_GRAY_TO_RGB_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_SWAP_ALPHA
+# define PNG_READ_SWAP_ALPHA_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_INVERT_ALPHA
+# define PNG_READ_INVERT_ALPHA_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_STRIP_ALPHA
+# define PNG_READ_STRIP_ALPHA_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_USER_TRANSFORM
+# define PNG_READ_USER_TRANSFORM_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_RGB_TO_GRAY
+# define PNG_READ_RGB_TO_GRAY_SUPPORTED
+# endif
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
+
+/* PNG_PROGRESSIVE_READ_NOT_SUPPORTED is deprecated. */
+#if !defined(PNG_NO_PROGRESSIVE_READ) && \
+ !defined(PNG_PROGRESSIVE_READ_NOT_SUPPORTED) /* if you don't do progressive */
+# define PNG_PROGRESSIVE_READ_SUPPORTED /* reading. This is not talking */
+#endif /* about interlacing capability! You'll */
+ /* still have interlacing unless you change the following define: */
+
+#define PNG_READ_INTERLACING_SUPPORTED /* required for PNG-compliant decoders */
+
+/* PNG_NO_SEQUENTIAL_READ_SUPPORTED is deprecated. */
+#if !defined(PNG_NO_SEQUENTIAL_READ) && \
+ !defined(PNG_SEQUENTIAL_READ_SUPPORTED) && \
+ !defined(PNG_NO_SEQUENTIAL_READ_SUPPORTED)
+# define PNG_SEQUENTIAL_READ_SUPPORTED
+#endif
+
+#ifndef PNG_NO_READ_COMPOSITE_NODIV
+# ifndef PNG_NO_READ_COMPOSITED_NODIV /* libpng-1.0.x misspelling */
+# define PNG_READ_COMPOSITE_NODIV_SUPPORTED /* well tested on Intel, SGI */
+# endif
+#endif
+
+#if !defined(PNG_NO_GET_INT_32) || defined(PNG_READ_oFFS_SUPPORTED) || \
+ defined(PNG_READ_pCAL_SUPPORTED)
+# ifndef PNG_GET_INT_32_SUPPORTED
+# define PNG_GET_INT_32_SUPPORTED
+# endif
+#endif
+
+#endif /* PNG_READ_SUPPORTED */
+
+#ifdef PNG_WRITE_SUPPORTED
+
+/* PNG_WRITE_TRANSFORMS_NOT_SUPPORTED is deprecated. */
+#if !defined(PNG_WRITE_TRANSFORMS_NOT_SUPPORTED) && \
+ !defined(PNG_NO_WRITE_TRANSFORMS)
+# define PNG_WRITE_TRANSFORMS_SUPPORTED
+#endif
+
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+# ifndef PNG_NO_WRITE_SHIFT
+# define PNG_WRITE_SHIFT_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_PACK
+# define PNG_WRITE_PACK_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_BGR
+# define PNG_WRITE_BGR_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_SWAP
+# define PNG_WRITE_SWAP_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_PACKSWAP
+# define PNG_WRITE_PACKSWAP_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_INVERT
+# define PNG_WRITE_INVERT_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_FILLER
+# define PNG_WRITE_FILLER_SUPPORTED /* same as WRITE_STRIP_ALPHA */
+# endif
+# ifndef PNG_NO_WRITE_SWAP_ALPHA
+# define PNG_WRITE_SWAP_ALPHA_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_INVERT_ALPHA
+# define PNG_WRITE_INVERT_ALPHA_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_USER_TRANSFORM
+# define PNG_WRITE_USER_TRANSFORM_SUPPORTED
+# endif
+#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
+
+#if !defined(PNG_NO_WRITE_INTERLACING_SUPPORTED) && \
+ !defined(PNG_WRITE_INTERLACING_SUPPORTED)
+ /* This is not required for PNG-compliant encoders, but can cause
+ * trouble if left undefined
+ */
+# define PNG_WRITE_INTERLACING_SUPPORTED
+#endif
+
+#if !defined(PNG_NO_WRITE_WEIGHTED_FILTER) && \
+ !defined(PNG_WRITE_WEIGHTED_FILTER) && \
+ defined(PNG_FLOATING_POINT_SUPPORTED)
+# define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+#endif
+
+#ifndef PNG_NO_WRITE_FLUSH
+# define PNG_WRITE_FLUSH_SUPPORTED
+#endif
+
+#if !defined(PNG_NO_SAVE_INT_32) || defined(PNG_WRITE_oFFS_SUPPORTED) || \
+ defined(PNG_WRITE_pCAL_SUPPORTED)
+# ifndef PNG_SAVE_INT_32_SUPPORTED
+# define PNG_SAVE_INT_32_SUPPORTED
+# endif
+#endif
+
+#endif /* PNG_WRITE_SUPPORTED */
+
+#define PNG_NO_ERROR_NUMBERS
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+# ifndef PNG_NO_USER_TRANSFORM_PTR
+# define PNG_USER_TRANSFORM_PTR_SUPPORTED
+# endif
+#endif
+
+#if defined(PNG_STDIO_SUPPORTED) && !defined(PNG_TIME_RFC1123_SUPPORTED)
+# define PNG_TIME_RFC1123_SUPPORTED
+#endif
+
+/* This adds extra functions in pngget.c for accessing data from the
+ * info pointer (added in version 0.99)
+ * png_get_image_width()
+ * png_get_image_height()
+ * png_get_bit_depth()
+ * png_get_color_type()
+ * png_get_compression_type()
+ * png_get_filter_type()
+ * png_get_interlace_type()
+ * png_get_pixel_aspect_ratio()
+ * png_get_pixels_per_meter()
+ * png_get_x_offset_pixels()
+ * png_get_y_offset_pixels()
+ * png_get_x_offset_microns()
+ * png_get_y_offset_microns()
+ */
+#if !defined(PNG_NO_EASY_ACCESS) && !defined(PNG_EASY_ACCESS_SUPPORTED)
+# define PNG_EASY_ACCESS_SUPPORTED
+#endif
+
+/* Added at libpng-1.2.0 */
+#if !defined(PNG_NO_USER_MEM) && !defined(PNG_USER_MEM_SUPPORTED)
+# define PNG_USER_MEM_SUPPORTED
+#endif
+
+/* Added at libpng-1.2.6 */
+#ifndef PNG_NO_SET_USER_LIMITS
+# ifndef PNG_SET_USER_LIMITS_SUPPORTED
+# define PNG_SET_USER_LIMITS_SUPPORTED
+# endif
+ /* Feature added at libpng-1.4.0, this flag added at 1.4.1 */
+# ifndef PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED
+# define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED
+# endif
+ /* Feature added at libpng-1.4.1, this flag added at 1.4.1 */
+# ifndef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+# define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+# endif
+#endif
+
+/* Added at libpng-1.2.43 */
+#ifndef PNG_USER_LIMITS_SUPPORTED
+# ifndef PNG_NO_USER_LIMITS
+# define PNG_USER_LIMITS_SUPPORTED
+# endif
+#endif
+
+/* Added at libpng-1.0.16 and 1.2.6. To accept all valid PNGs no matter
+ * how large, set these two limits to 0x7fffffffL
+ */
+#ifndef PNG_USER_WIDTH_MAX
+# define PNG_USER_WIDTH_MAX 1000000L
+#endif
+#ifndef PNG_USER_HEIGHT_MAX
+# define PNG_USER_HEIGHT_MAX 1000000L
+#endif
+
+/* Added at libpng-1.2.43. To accept all valid PNGs no matter
+ * how large, set these two limits to 0.
+ */
+#ifndef PNG_USER_CHUNK_CACHE_MAX
+# define PNG_USER_CHUNK_CACHE_MAX 0
+#endif
+
+/* Added at libpng-1.2.43 */
+#ifndef PNG_USER_CHUNK_MALLOC_MAX
+# define PNG_USER_CHUNK_MALLOC_MAX 0
+#endif
+
+/* Added at libpng-1.4.0 */
+#if !defined(PNG_NO_IO_STATE) && !defined(PNG_IO_STATE_SUPPORTED)
+# define PNG_IO_STATE_SUPPORTED
+#endif
+
+#ifndef PNG_LITERAL_SHARP
+# define PNG_LITERAL_SHARP 0x23
+#endif
+#ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET
+# define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b
+#endif
+#ifndef PNG_LITERAL_RIGHT_SQUARE_BRACKET
+# define PNG_LITERAL_RIGHT_SQUARE_BRACKET 0x5d
+#endif
+#ifndef PNG_STRING_NEWLINE
+#define PNG_STRING_NEWLINE "\n"
+#endif
+
+/* These are currently experimental features, define them if you want */
+
+/* Very little testing */
+/*
+#ifdef PNG_READ_SUPPORTED
+# ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+# define PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+# endif
+#endif
+*/
+
+/* This is only for PowerPC big-endian and 680x0 systems */
+/* some testing */
+/*
+#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
+# define PNG_READ_BIG_ENDIAN_SUPPORTED
+#endif
+*/
+
+#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS)
+# define PNG_USE_READ_MACROS
+#endif
+
+/* Buggy compilers (e.g., gcc 2.7.2.2) need PNG_NO_POINTER_INDEXING */
+
+#if !defined(PNG_NO_POINTER_INDEXING) && \
+ !defined(PNG_POINTER_INDEXING_SUPPORTED)
+# define PNG_POINTER_INDEXING_SUPPORTED
+#endif
+
+
+/* Any chunks you are not interested in, you can undef here. The
+ * ones that allocate memory may be expecially important (hIST,
+ * tEXt, zTXt, tRNS, pCAL). Others will just save time and make png_info
+ * a bit smaller.
+ */
+
+/* The size of the png_text structure changed in libpng-1.0.6 when
+ * iTXt support was added. iTXt support was turned off by default through
+ * libpng-1.2.x, to support old apps that malloc the png_text structure
+ * instead of calling png_set_text() and letting libpng malloc it. It
+ * was turned on by default in libpng-1.4.0.
+ */
+
+/* PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED is deprecated. */
+#if defined(PNG_READ_SUPPORTED) && \
+ !defined(PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED) && \
+ !defined(PNG_NO_READ_ANCILLARY_CHUNKS)
+# define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+#endif
+
+/* PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED is deprecated. */
+#if defined(PNG_WRITE_SUPPORTED) && \
+ !defined(PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED) && \
+ !defined(PNG_NO_WRITE_ANCILLARY_CHUNKS)
+# define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+#endif
+
+#ifdef PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+
+#ifdef PNG_NO_READ_TEXT
+# define PNG_NO_READ_iTXt
+# define PNG_NO_READ_tEXt
+# define PNG_NO_READ_zTXt
+#endif
+
+#ifndef PNG_NO_READ_bKGD
+# define PNG_READ_bKGD_SUPPORTED
+# define PNG_bKGD_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_cHRM
+# define PNG_READ_cHRM_SUPPORTED
+# define PNG_cHRM_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_gAMA
+# define PNG_READ_gAMA_SUPPORTED
+# define PNG_gAMA_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_hIST
+# define PNG_READ_hIST_SUPPORTED
+# define PNG_hIST_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_iCCP
+# define PNG_READ_iCCP_SUPPORTED
+# define PNG_iCCP_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_iTXt
+# ifndef PNG_READ_iTXt_SUPPORTED
+# define PNG_READ_iTXt_SUPPORTED
+# endif
+# ifndef PNG_iTXt_SUPPORTED
+# define PNG_iTXt_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_READ_oFFs
+# define PNG_READ_oFFs_SUPPORTED
+# define PNG_oFFs_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_pCAL
+# define PNG_READ_pCAL_SUPPORTED
+# define PNG_pCAL_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sCAL
+# define PNG_READ_sCAL_SUPPORTED
+# define PNG_sCAL_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_pHYs
+# define PNG_READ_pHYs_SUPPORTED
+# define PNG_pHYs_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sBIT
+# define PNG_READ_sBIT_SUPPORTED
+# define PNG_sBIT_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sPLT
+# define PNG_READ_sPLT_SUPPORTED
+# define PNG_sPLT_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sRGB
+# define PNG_READ_sRGB_SUPPORTED
+# define PNG_sRGB_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_tEXt
+# define PNG_READ_tEXt_SUPPORTED
+# define PNG_tEXt_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_tIME
+# define PNG_READ_tIME_SUPPORTED
+# define PNG_tIME_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_tRNS
+# define PNG_READ_tRNS_SUPPORTED
+# define PNG_tRNS_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_zTXt
+# define PNG_READ_zTXt_SUPPORTED
+# define PNG_zTXt_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_OPT_PLTE
+# define PNG_READ_OPT_PLTE_SUPPORTED /* only affects support of the */
+#endif /* optional PLTE chunk in RGB and RGBA images */
+#if defined(PNG_READ_iTXt_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) || \
+ defined(PNG_READ_zTXt_SUPPORTED)
+# define PNG_READ_TEXT_SUPPORTED
+# define PNG_TEXT_SUPPORTED
+#endif
+
+#endif /* PNG_READ_ANCILLARY_CHUNKS_SUPPORTED */
+
+#ifndef PNG_NO_READ_UNKNOWN_CHUNKS
+# ifndef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+# define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+# endif
+# ifndef PNG_UNKNOWN_CHUNKS_SUPPORTED
+# define PNG_UNKNOWN_CHUNKS_SUPPORTED
+# endif
+# ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+# define PNG_READ_USER_CHUNKS_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_READ_USER_CHUNKS
+# ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+# define PNG_READ_USER_CHUNKS_SUPPORTED
+# endif
+# ifndef PNG_USER_CHUNKS_SUPPORTED
+# define PNG_USER_CHUNKS_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_HANDLE_AS_UNKNOWN
+# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+# define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+# endif
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+
+#ifdef PNG_NO_WRITE_TEXT
+# define PNG_NO_WRITE_iTXt
+# define PNG_NO_WRITE_tEXt
+# define PNG_NO_WRITE_zTXt
+#endif
+#ifndef PNG_NO_WRITE_bKGD
+# define PNG_WRITE_bKGD_SUPPORTED
+# ifndef PNG_bKGD_SUPPORTED
+# define PNG_bKGD_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_cHRM
+# define PNG_WRITE_cHRM_SUPPORTED
+# ifndef PNG_cHRM_SUPPORTED
+# define PNG_cHRM_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_gAMA
+# define PNG_WRITE_gAMA_SUPPORTED
+# ifndef PNG_gAMA_SUPPORTED
+# define PNG_gAMA_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_hIST
+# define PNG_WRITE_hIST_SUPPORTED
+# ifndef PNG_hIST_SUPPORTED
+# define PNG_hIST_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_iCCP
+# define PNG_WRITE_iCCP_SUPPORTED
+# ifndef PNG_iCCP_SUPPORTED
+# define PNG_iCCP_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_iTXt
+# ifndef PNG_WRITE_iTXt_SUPPORTED
+# define PNG_WRITE_iTXt_SUPPORTED
+# endif
+# ifndef PNG_iTXt_SUPPORTED
+# define PNG_iTXt_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_oFFs
+# define PNG_WRITE_oFFs_SUPPORTED
+# ifndef PNG_oFFs_SUPPORTED
+# define PNG_oFFs_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_pCAL
+# define PNG_WRITE_pCAL_SUPPORTED
+# ifndef PNG_pCAL_SUPPORTED
+# define PNG_pCAL_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_sCAL
+# define PNG_WRITE_sCAL_SUPPORTED
+# ifndef PNG_sCAL_SUPPORTED
+# define PNG_sCAL_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_pHYs
+# define PNG_WRITE_pHYs_SUPPORTED
+# ifndef PNG_pHYs_SUPPORTED
+# define PNG_pHYs_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_sBIT
+# define PNG_WRITE_sBIT_SUPPORTED
+# ifndef PNG_sBIT_SUPPORTED
+# define PNG_sBIT_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_sPLT
+# define PNG_WRITE_sPLT_SUPPORTED
+# ifndef PNG_sPLT_SUPPORTED
+# define PNG_sPLT_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_sRGB
+# define PNG_WRITE_sRGB_SUPPORTED
+# ifndef PNG_sRGB_SUPPORTED
+# define PNG_sRGB_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_tEXt
+# define PNG_WRITE_tEXt_SUPPORTED
+# ifndef PNG_tEXt_SUPPORTED
+# define PNG_tEXt_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_tIME
+# define PNG_WRITE_tIME_SUPPORTED
+# ifndef PNG_tIME_SUPPORTED
+# define PNG_tIME_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_tRNS
+# define PNG_WRITE_tRNS_SUPPORTED
+# ifndef PNG_tRNS_SUPPORTED
+# define PNG_tRNS_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_zTXt
+# define PNG_WRITE_zTXt_SUPPORTED
+# ifndef PNG_zTXt_SUPPORTED
+# define PNG_zTXt_SUPPORTED
+# endif
+#endif
+#if defined(PNG_WRITE_iTXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \
+ defined(PNG_WRITE_zTXt_SUPPORTED)
+# define PNG_WRITE_TEXT_SUPPORTED
+# ifndef PNG_TEXT_SUPPORTED
+# define PNG_TEXT_SUPPORTED
+# endif
+#endif
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+# ifndef PNG_NO_CONVERT_tIME
+# ifndef _WIN32_WCE
+/* The "tm" structure is not supported on WindowsCE */
+# ifndef PNG_CONVERT_tIME_SUPPORTED
+# define PNG_CONVERT_tIME_SUPPORTED
+# endif
+# endif
+# endif
+#endif
+
+#endif /* PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED */
+
+#ifndef PNG_NO_WRITE_FILTER
+# ifndef PNG_WRITE_FILTER_SUPPORTED
+# define PNG_WRITE_FILTER_SUPPORTED
+# endif
+#endif
+
+#ifndef PNG_NO_WRITE_UNKNOWN_CHUNKS
+# define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+# ifndef PNG_UNKNOWN_CHUNKS_SUPPORTED
+# define PNG_UNKNOWN_CHUNKS_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_HANDLE_AS_UNKNOWN
+# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+# define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+# endif
+#endif
+#endif /* PNG_WRITE_SUPPORTED */
+
+/* Turn this off to disable png_read_png() and
+ * png_write_png() and leave the row_pointers member
+ * out of the info structure.
+ */
+#ifndef PNG_NO_INFO_IMAGE
+# define PNG_INFO_IMAGE_SUPPORTED
+#endif
+
+/* Need the time information for converting tIME chunks */
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+ /* "time.h" functions are not supported on WindowsCE */
+# include <time.h>
+#endif
+
+/* Some typedefs to get us started. These should be safe on most of the
+ * common platforms. The typedefs should be at least as large as the
+ * numbers suggest (a png_uint_32 must be at least 32 bits long), but they
+ * don't have to be exactly that size. Some compilers dislike passing
+ * unsigned shorts as function parameters, so you may be better off using
+ * unsigned int for png_uint_16.
+ */
+
+#if defined(INT_MAX) && (INT_MAX > 0x7ffffffeL)
+typedef unsigned int png_uint_32;
+typedef int png_int_32;
+#else
+typedef unsigned long png_uint_32;
+typedef long png_int_32;
+#endif
+typedef unsigned short png_uint_16;
+typedef short png_int_16;
+typedef unsigned char png_byte;
+
+#ifdef PNG_NO_SIZE_T
+ typedef unsigned int png_size_t;
+#else
+ typedef size_t png_size_t;
+#endif
+#define png_sizeof(x) (sizeof (x))
+
+/* The following is needed for medium model support. It cannot be in the
+ * pngpriv.h header. Needs modification for other compilers besides
+ * MSC. Model independent support declares all arrays and pointers to be
+ * large using the far keyword. The zlib version used must also support
+ * model independent data. As of version zlib 1.0.4, the necessary changes
+ * have been made in zlib. The USE_FAR_KEYWORD define triggers other
+ * changes that are needed. (Tim Wegner)
+ */
+
+/* Separate compiler dependencies (problem here is that zlib.h always
+ * defines FAR. (SJT)
+ */
+#ifdef __BORLANDC__
+# if defined(__LARGE__) || defined(__HUGE__) || defined(__COMPACT__)
+# define LDATA 1
+# else
+# define LDATA 0
+# endif
+ /* GRR: why is Cygwin in here? Cygwin is not Borland C... */
+# if !defined(__WIN32__) && !defined(__FLAT__) && !defined(__CYGWIN__)
+# define PNG_MAX_MALLOC_64K
+# if (LDATA != 1)
+# ifndef FAR
+# define FAR __far
+# endif
+# define USE_FAR_KEYWORD
+# endif /* LDATA != 1 */
+ /* Possibly useful for moving data out of default segment.
+ * Uncomment it if you want. Could also define FARDATA as
+ * const if your compiler supports it. (SJT)
+# define FARDATA FAR
+ */
+# endif /* __WIN32__, __FLAT__, __CYGWIN__ */
+#endif /* __BORLANDC__ */
+
+
+/* Suggest testing for specific compiler first before testing for
+ * FAR. The Watcom compiler defines both __MEDIUM__ and M_I86MM,
+ * making reliance oncertain keywords suspect. (SJT)
+ */
+
+/* MSC Medium model */
+#ifdef FAR
+# ifdef M_I86MM
+# define USE_FAR_KEYWORD
+# define FARDATA FAR
+# include <dos.h>
+# endif
+#endif
+
+/* SJT: default case */
+#ifndef FAR
+# define FAR
+#endif
+
+/* At this point FAR is always defined */
+#ifndef FARDATA
+# define FARDATA
+#endif
+
+/* Typedef for floating-point numbers that are converted
+ to fixed-point with a multiple of 100,000, e.g., int_gamma */
+typedef png_int_32 png_fixed_point;
+
+/* Add typedefs for pointers */
+typedef void FAR * png_voidp;
+typedef png_byte FAR * png_bytep;
+typedef png_uint_32 FAR * png_uint_32p;
+typedef png_int_32 FAR * png_int_32p;
+typedef png_uint_16 FAR * png_uint_16p;
+typedef png_int_16 FAR * png_int_16p;
+typedef PNG_CONST char FAR * png_const_charp;
+typedef char FAR * png_charp;
+typedef png_fixed_point FAR * png_fixed_point_p;
+
+#ifndef PNG_NO_STDIO
+typedef FILE * png_FILE_p;
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double FAR * png_doublep;
+#endif
+
+/* Pointers to pointers; i.e. arrays */
+typedef png_byte FAR * FAR * png_bytepp;
+typedef png_uint_32 FAR * FAR * png_uint_32pp;
+typedef png_int_32 FAR * FAR * png_int_32pp;
+typedef png_uint_16 FAR * FAR * png_uint_16pp;
+typedef png_int_16 FAR * FAR * png_int_16pp;
+typedef PNG_CONST char FAR * FAR * png_const_charpp;
+typedef char FAR * FAR * png_charpp;
+typedef png_fixed_point FAR * FAR * png_fixed_point_pp;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double FAR * FAR * png_doublepp;
+#endif
+
+/* Pointers to pointers to pointers; i.e., pointer to array */
+typedef char FAR * FAR * FAR * png_charppp;
+
+/* Define PNG_BUILD_DLL if the module being built is a Windows
+ * LIBPNG DLL.
+ *
+ * Define PNG_USE_DLL if you want to *link* to the Windows LIBPNG DLL.
+ * It is equivalent to Microsoft predefined macro _DLL that is
+ * automatically defined when you compile using the share
+ * version of the CRT (C Run-Time library)
+ *
+ * The cygwin mods make this behavior a little different:
+ * Define PNG_BUILD_DLL if you are building a dll for use with cygwin
+ * Define PNG_STATIC if you are building a static library for use with cygwin,
+ * -or- if you are building an application that you want to link to the
+ * static library.
+ * PNG_USE_DLL is defined by default (no user action needed) unless one of
+ * the other flags is defined.
+ */
+
+#if !defined(PNG_DLL) && (defined(PNG_BUILD_DLL) || defined(PNG_USE_DLL))
+# define PNG_DLL
+#endif
+
+/* If you define PNGAPI, e.g., with compiler option "-DPNGAPI=__stdcall",
+ * you may get warnings regarding the linkage of png_zalloc and png_zfree.
+ * Don't ignore those warnings; you must also reset the default calling
+ * convention in your compiler to match your PNGAPI, and you must build
+ * zlib and your applications the same way you build libpng.
+ */
+
+#ifdef __CYGWIN__
+# undef PNGAPI
+# define PNGAPI __cdecl
+# undef PNG_IMPEXP
+# define PNG_IMPEXP
+#endif
+
+#ifdef __WATCOMC__
+# ifndef PNGAPI
+# define PNGAPI
+# endif
+#endif
+
+#if defined(__MINGW32__) && !defined(PNG_MODULEDEF)
+# ifndef PNG_NO_MODULEDEF
+# define PNG_NO_MODULEDEF
+# endif
+#endif
+
+#if !defined(PNG_IMPEXP) && defined(PNG_BUILD_DLL) && !defined(PNG_NO_MODULEDEF)
+# define PNG_IMPEXP
+#endif
+
+#if defined(PNG_DLL) || defined(_DLL) || defined(__DLL__ ) || \
+ (( defined(_Windows) || defined(_WINDOWS) || \
+ defined(WIN32) || defined(_WIN32) || defined(__WIN32__) ))
+
+# ifndef PNGAPI
+# if defined(__GNUC__) || (defined (_MSC_VER) && (_MSC_VER >= 800))
+# define PNGAPI __cdecl
+# else
+# define PNGAPI _cdecl
+# endif
+# endif
+
+# if !defined(PNG_IMPEXP) && (!defined(PNG_DLL) || \
+ 0 /* WINCOMPILER_WITH_NO_SUPPORT_FOR_DECLIMPEXP */)
+# define PNG_IMPEXP
+# endif
+
+# ifndef PNG_IMPEXP
+
+# define PNG_EXPORT_TYPE1(type,symbol) PNG_IMPEXP type PNGAPI symbol
+# define PNG_EXPORT_TYPE2(type,symbol) type PNG_IMPEXP PNGAPI symbol
+
+ /* Borland/Microsoft */
+# if defined(_MSC_VER) || defined(__BORLANDC__)
+# if (_MSC_VER >= 800) || (__BORLANDC__ >= 0x500)
+# define PNG_EXPORT PNG_EXPORT_TYPE1
+# else
+# define PNG_EXPORT PNG_EXPORT_TYPE2
+# ifdef PNG_BUILD_DLL
+# define PNG_IMPEXP __export
+# else
+# define PNG_IMPEXP /*__import */ /* doesn't exist AFAIK in VC++ */
+# endif /* Exists in Borland C++ for
+ C++ classes (== huge) */
+# endif
+# endif
+
+# ifndef PNG_IMPEXP
+# ifdef PNG_BUILD_DLL
+# define PNG_IMPEXP __declspec(dllexport)
+# else
+# define PNG_IMPEXP __declspec(dllimport)
+# endif
+# endif
+# endif /* PNG_IMPEXP */
+#else /* !(DLL || non-cygwin WINDOWS) */
+# if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
+# ifndef PNGAPI
+# define PNGAPI _System
+# endif
+# else
+# if 0 /* ... other platforms, with other meanings */
+# endif
+# endif
+#endif
+
+#ifndef PNGAPI
+# define PNGAPI
+#endif
+#ifndef PNG_IMPEXP
+# define PNG_IMPEXP
+#endif
+
+#ifdef PNG_BUILDSYMS
+# ifndef PNG_EXPORT
+# define PNG_EXPORT(type,symbol) PNG_FUNCTION_EXPORT symbol END
+# endif
+#endif
+
+#ifndef PNG_EXPORT
+# define PNG_EXPORT(type,symbol) PNG_IMPEXP type PNGAPI symbol
+#endif
+
+#define PNG_USE_LOCAL_ARRAYS /* Not used in libpng, defined for legacy apps */
+
+/* Support for compiler specific function attributes. These are used
+ * so that where compiler support is available incorrect use of API
+ * functions in png.h will generate compiler warnings.
+ *
+ * Added at libpng-1.2.41.
+ */
+
+#ifndef PNG_NO_PEDANTIC_WARNINGS
+# ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED
+# define PNG_PEDANTIC_WARNINGS_SUPPORTED
+# endif
+#endif
+
+#ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED
+/* Support for compiler specific function attributes. These are used
+ * so that where compiler support is available incorrect use of API
+ * functions in png.h will generate compiler warnings. Added at libpng
+ * version 1.2.41.
+ */
+# ifdef __GNUC__
+# ifndef PNG_USE_RESULT
+# define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+# endif
+# ifndef PNG_NORETURN
+# define PNG_NORETURN __attribute__((__noreturn__))
+# endif
+# ifndef PNG_ALLOCATED
+# define PNG_ALLOCATED __attribute__((__malloc__))
+# endif
+
+ /* This specifically protects structure members that should only be
+ * accessed from within the library, therefore should be empty during
+ * a library build.
+ */
+# ifndef PNG_DEPRECATED
+# define PNG_DEPRECATED __attribute__((__deprecated__))
+# endif
+# ifndef PNG_DEPSTRUCT
+# define PNG_DEPSTRUCT __attribute__((__deprecated__))
+# endif
+# ifndef PNG_PRIVATE
+# if 0 /* Doesn't work so we use deprecated instead*/
+# define PNG_PRIVATE \
+ __attribute__((warning("This function is not exported by libpng.")))
+# else
+# define PNG_PRIVATE \
+ __attribute__((__deprecated__))
+# endif
+# endif /* PNG_PRIVATE */
+# endif /* __GNUC__ */
+#endif /* PNG_PEDANTIC_WARNINGS */
+
+#ifndef PNG_DEPRECATED
+# define PNG_DEPRECATED /* Use of this function is deprecated */
+#endif
+#ifndef PNG_USE_RESULT
+# define PNG_USE_RESULT /* The result of this function must be checked */
+#endif
+#ifndef PNG_NORETURN
+# define PNG_NORETURN /* This function does not return */
+#endif
+#ifndef PNG_ALLOCATED
+# define PNG_ALLOCATED /* The result of the function is new memory */
+#endif
+#ifndef PNG_DEPSTRUCT
+# define PNG_DEPSTRUCT /* Access to this struct member is deprecated */
+#endif
+#ifndef PNG_PRIVATE
+# define PNG_PRIVATE /* This is a private libpng function */
+#endif
+
+/* Users may want to use these so they are not private. Any library
+ * functions that are passed far data must be model-independent.
+ */
+
+/* memory model/platform independent fns */
+#ifndef PNG_ABORT
+# if (defined(_Windows) || defined(_WINDOWS) || defined(_WINDOWS_))
+# define PNG_ABORT() ExitProcess(0)
+# else
+# define PNG_ABORT() abort()
+# endif
+#endif
+
+#ifdef USE_FAR_KEYWORD
+/* Use this to make far-to-near assignments */
+# define CHECK 1
+# define NOCHECK 0
+# define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
+# define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
+# define png_strcpy _fstrcpy
+# define png_strncpy _fstrncpy /* Added to v 1.2.6 */
+# define png_strlen _fstrlen
+# define png_memcmp _fmemcmp /* SJT: added */
+# define png_memcpy _fmemcpy
+# define png_memset _fmemset
+# define png_sprintf sprintf
+#else
+# if (defined(_Windows) || defined(_WINDOWS) || defined(_WINDOWS_))
+# /* Favor Windows over C runtime fns */
+# define CVT_PTR(ptr) (ptr)
+# define CVT_PTR_NOCHECK(ptr) (ptr)
+# define png_strcpy lstrcpyA
+# define png_strncpy lstrcpynA
+# define png_strlen lstrlenA
+# define png_memcmp memcmp
+# define png_memcpy CopyMemory
+# define png_memset memset
+# define png_sprintf wsprintfA
+# else
+# define CVT_PTR(ptr) (ptr)
+# define CVT_PTR_NOCHECK(ptr) (ptr)
+# define png_strcpy strcpy
+# define png_strncpy strncpy /* Added to v 1.2.6 */
+# define png_strlen strlen
+# define png_memcmp memcmp /* SJT: added */
+# define png_memcpy memcpy
+# define png_memset memset
+# define png_sprintf sprintf
+# endif
+#endif
+
+#ifndef PNG_NO_SNPRINTF
+# ifdef _MSC_VER
+# define png_snprintf _snprintf /* Added to v 1.2.19 */
+# define png_snprintf2 _snprintf
+# define png_snprintf6 _snprintf
+# else
+# define png_snprintf snprintf /* Added to v 1.2.19 */
+# define png_snprintf2 snprintf
+# define png_snprintf6 snprintf
+# endif
+#else
+ /* You don't have or don't want to use snprintf(). Caution: Using
+ * sprintf instead of snprintf exposes your application to accidental
+ * or malevolent buffer overflows. If you don't have snprintf()
+ * as a general rule you should provide one (you can get one from
+ * Portable OpenSSH).
+ */
+# define png_snprintf(s1,n,fmt,x1) png_sprintf(s1,fmt,x1)
+# define png_snprintf2(s1,n,fmt,x1,x2) png_sprintf(s1,fmt,x1,x2)
+# define png_snprintf6(s1,n,fmt,x1,x2,x3,x4,x5,x6) \
+ png_sprintf(s1,fmt,x1,x2,x3,x4,x5,x6)
+#endif
+
+/* png_alloc_size_t is guaranteed to be no smaller than png_size_t,
+ * and no smaller than png_uint_32. Casts from png_size_t or png_uint_32
+ * to png_alloc_size_t are not necessary; in fact, it is recommended
+ * not to use them at all so that the compiler can complain when something
+ * turns out to be problematic.
+ * Casts in the other direction (from png_alloc_size_t to png_size_t or
+ * png_uint_32) should be explicitly applied; however, we do not expect
+ * to encounter practical situations that require such conversions.
+ */
+#if defined(__TURBOC__) && !defined(__FLAT__)
+ typedef unsigned long png_alloc_size_t;
+#else
+# if defined(_MSC_VER) && defined(MAXSEG_64K)
+ typedef unsigned long png_alloc_size_t;
+# else
+ /* This is an attempt to detect an old Windows system where (int) is
+ * actually 16 bits, in that case png_malloc must have an argument with a
+ * bigger size to accomodate the requirements of the library.
+ */
+# if (defined(_Windows) || defined(_WINDOWS) || defined(_WINDOWS_)) && \
+ (!defined(INT_MAX) || INT_MAX <= 0x7ffffffeL)
+ typedef DWORD png_alloc_size_t;
+# else
+ typedef png_size_t png_alloc_size_t;
+# endif
+# endif
+#endif
+/* End of memory model/platform independent support */
+
+/* Just a little check that someone hasn't tried to define something
+ * contradictory.
+ */
+#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
+# undef PNG_ZBUF_SIZE
+# define PNG_ZBUF_SIZE 65536L
+#endif
+
+
+/* Added at libpng-1.2.8 */
+#endif /* PNG_VERSION_INFO_ONLY */
+
+#endif /* PNGCONF_H */
--- /dev/null
+
+/* pngerror.c - stub functions for i/o and memory allocation
+ *
+ * Last changed in libpng 1.4.0 [January 3, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all error handling. Users who
+ * need special error handling are expected to write replacement functions
+ * and use png_set_error_fn() to use those functions. See the instructions
+ * at each function.
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#include "pngpriv.h"
+
+static void /* PRIVATE */
+png_default_error PNGARG((png_structp png_ptr,
+ png_const_charp error_message)) PNG_NORETURN;
+#ifdef PNG_WARNINGS_SUPPORTED
+static void /* PRIVATE */
+png_default_warning PNGARG((png_structp png_ptr,
+ png_const_charp warning_message));
+#endif /* PNG_WARNINGS_SUPPORTED */
+
+/* This function is called whenever there is a fatal error. This function
+ * should not be changed. If there is a need to handle errors differently,
+ * you should supply a replacement error function and use png_set_error_fn()
+ * to replace the error function at run-time.
+ */
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+void PNGAPI
+png_error(png_structp png_ptr, png_const_charp error_message)
+{
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ char msg[16];
+ if (png_ptr != NULL)
+ {
+ if (png_ptr->flags&
+ (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+ {
+ if (*error_message == PNG_LITERAL_SHARP)
+ {
+ /* Strip "#nnnn " from beginning of error message. */
+ int offset;
+ for (offset = 1; offset<15; offset++)
+ if (error_message[offset] == ' ')
+ break;
+ if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+ {
+ int i;
+ for (i = 0; i < offset - 1; i++)
+ msg[i] = error_message[i + 1];
+ msg[i - 1] = '\0';
+ error_message = msg;
+ }
+ else
+ error_message += offset;
+ }
+ else
+ {
+ if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+ {
+ msg[0] = '0';
+ msg[1] = '\0';
+ error_message = msg;
+ }
+ }
+ }
+ }
+#endif
+ if (png_ptr != NULL && png_ptr->error_fn != NULL)
+ (*(png_ptr->error_fn))(png_ptr, error_message);
+
+ /* If the custom handler doesn't exist, or if it returns,
+ use the default handler, which will not return. */
+ png_default_error(png_ptr, error_message);
+}
+#else
+void PNGAPI
+png_err(png_structp png_ptr)
+{
+ if (png_ptr != NULL && png_ptr->error_fn != NULL)
+ (*(png_ptr->error_fn))(png_ptr, '\0');
+
+ /* If the custom handler doesn't exist, or if it returns,
+ use the default handler, which will not return. */
+ png_default_error(png_ptr, '\0');
+}
+#endif /* PNG_ERROR_TEXT_SUPPORTED */
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called whenever there is a non-fatal error. This function
+ * should not be changed. If there is a need to handle warnings differently,
+ * you should supply a replacement warning function and use
+ * png_set_error_fn() to replace the warning function at run-time.
+ */
+void PNGAPI
+png_warning(png_structp png_ptr, png_const_charp warning_message)
+{
+ int offset = 0;
+ if (png_ptr != NULL)
+ {
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ if (png_ptr->flags&
+ (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+#endif
+ {
+ if (*warning_message == PNG_LITERAL_SHARP)
+ {
+ for (offset = 1; offset < 15; offset++)
+ if (warning_message[offset] == ' ')
+ break;
+ }
+ }
+ }
+ if (png_ptr != NULL && png_ptr->warning_fn != NULL)
+ (*(png_ptr->warning_fn))(png_ptr, warning_message + offset);
+ else
+ png_default_warning(png_ptr, warning_message + offset);
+}
+#endif /* PNG_WARNINGS_SUPPORTED */
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_benign_error(png_structp png_ptr, png_const_charp error_message)
+{
+ if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
+ png_warning(png_ptr, error_message);
+ else
+ png_error(png_ptr, error_message);
+}
+#endif
+
+/* These utilities are used internally to build an error message that relates
+ * to the current chunk. The chunk name comes from png_ptr->chunk_name,
+ * this is used to prefix the message. The message is limited in length
+ * to 63 bytes, the name characters are output as hex digits wrapped in []
+ * if the character is invalid.
+ */
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+static PNG_CONST char png_digit[16] = {
+ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+ 'A', 'B', 'C', 'D', 'E', 'F'
+};
+
+#define PNG_MAX_ERROR_TEXT 64
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
+static void /* PRIVATE */
+png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
+ error_message)
+{
+ int iout = 0, iin = 0;
+
+ while (iin < 4)
+ {
+ int c = png_ptr->chunk_name[iin++];
+ if (isnonalpha(c))
+ {
+ buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
+ buffer[iout++] = png_digit[(c & 0xf0) >> 4];
+ buffer[iout++] = png_digit[c & 0x0f];
+ buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
+ }
+ else
+ {
+ buffer[iout++] = (png_byte)c;
+ }
+ }
+
+ if (error_message == NULL)
+ buffer[iout] = '\0';
+ else
+ {
+ buffer[iout++] = ':';
+ buffer[iout++] = ' ';
+ png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT);
+ buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0';
+ }
+}
+
+#ifdef PNG_READ_SUPPORTED
+void PNGAPI
+png_chunk_error(png_structp png_ptr, png_const_charp error_message)
+{
+ char msg[18+PNG_MAX_ERROR_TEXT];
+ if (png_ptr == NULL)
+ png_error(png_ptr, error_message);
+ else
+ {
+ png_format_buffer(png_ptr, msg, error_message);
+ png_error(png_ptr, msg);
+ }
+}
+#endif /* PNG_READ_SUPPORTED */
+#endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
+
+#ifdef PNG_WARNINGS_SUPPORTED
+void PNGAPI
+png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
+{
+ char msg[18+PNG_MAX_ERROR_TEXT];
+ if (png_ptr == NULL)
+ png_warning(png_ptr, warning_message);
+ else
+ {
+ png_format_buffer(png_ptr, msg, warning_message);
+ png_warning(png_ptr, msg);
+ }
+}
+#endif /* PNG_WARNINGS_SUPPORTED */
+
+#ifdef PNG_READ_SUPPORTED
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_chunk_benign_error(png_structp png_ptr, png_const_charp error_message)
+{
+ if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
+ png_chunk_warning(png_ptr, error_message);
+ else
+ png_chunk_error(png_ptr, error_message);
+}
+#endif
+#endif /* PNG_READ_SUPPORTED */
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* This API only exists if ANSI-C style error handling is used,
+ * otherwise it is necessary for png_default_error to be overridden.
+ */
+jmp_buf* PNGAPI
+png_set_longjmp_fn(png_structp png_ptr, png_longjmp_ptr longjmp_fn,
+ size_t jmp_buf_size)
+{
+ if (png_ptr == NULL || jmp_buf_size != png_sizeof(jmp_buf))
+ return NULL;
+
+ png_ptr->longjmp_fn = longjmp_fn;
+ return &png_ptr->jmpbuf;
+}
+#endif
+
+/* This is the default error handling function. Note that replacements for
+ * this function MUST NOT RETURN, or the program will likely crash. This
+ * function is used by default, or if the program supplies NULL for the
+ * error function pointer in png_set_error_fn().
+ */
+static void /* PRIVATE */
+png_default_error(png_structp png_ptr, png_const_charp error_message)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ if (*error_message == PNG_LITERAL_SHARP)
+ {
+ /* Strip "#nnnn " from beginning of error message. */
+ int offset;
+ char error_number[16];
+ for (offset = 0; offset<15; offset++)
+ {
+ error_number[offset] = error_message[offset + 1];
+ if (error_message[offset] == ' ')
+ break;
+ }
+ if ((offset > 1) && (offset < 15))
+ {
+ error_number[offset - 1] = '\0';
+ fprintf(stderr, "libpng error no. %s: %s",
+ error_number, error_message + offset + 1);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+ else
+ {
+ fprintf(stderr, "libpng error: %s, offset=%d",
+ error_message, offset);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+ }
+ else
+#endif
+ {
+ fprintf(stderr, "libpng error: %s", error_message);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+ if (png_ptr && png_ptr->longjmp_fn)
+ {
+# ifdef USE_FAR_KEYWORD
+ {
+ jmp_buf jmpbuf;
+ png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf));
+ png_ptr->longjmp_fn(jmpbuf, 1);
+ }
+# else
+ png_ptr->longjmp_fn(png_ptr->jmpbuf, 1);
+# endif
+ }
+#endif
+ /* Here if not setjmp support or if png_ptr is null. */
+ PNG_ABORT();
+#ifndef PNG_CONSOLE_IO_SUPPORTED
+ error_message = error_message; /* Make compiler happy */
+#endif
+}
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called when there is a warning, but the library thinks
+ * it can continue anyway. Replacement functions don't have to do anything
+ * here if you don't want them to. In the default configuration, png_ptr is
+ * not used, but it is passed in case it may be useful.
+ */
+static void /* PRIVATE */
+png_default_warning(png_structp png_ptr, png_const_charp warning_message)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+# ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ if (*warning_message == PNG_LITERAL_SHARP)
+ {
+ int offset;
+ char warning_number[16];
+ for (offset = 0; offset < 15; offset++)
+ {
+ warning_number[offset] = warning_message[offset + 1];
+ if (warning_message[offset] == ' ')
+ break;
+ }
+ if ((offset > 1) && (offset < 15))
+ {
+ warning_number[offset + 1] = '\0';
+ fprintf(stderr, "libpng warning no. %s: %s",
+ warning_number, warning_message + offset);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+ else
+ {
+ fprintf(stderr, "libpng warning: %s",
+ warning_message);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+ }
+ else
+# endif
+ {
+ fprintf(stderr, "libpng warning: %s", warning_message);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+#else
+ warning_message = warning_message; /* Make compiler happy */
+#endif
+ png_ptr = png_ptr; /* Make compiler happy */
+}
+#endif /* PNG_WARNINGS_SUPPORTED */
+
+/* This function is called when the application wants to use another method
+ * of handling errors and warnings. Note that the error function MUST NOT
+ * return to the calling routine or serious problems will occur. The return
+ * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
+ */
+void PNGAPI
+png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warning_fn)
+{
+ if (png_ptr == NULL)
+ return;
+ png_ptr->error_ptr = error_ptr;
+ png_ptr->error_fn = error_fn;
+ png_ptr->warning_fn = warning_fn;
+}
+
+
+/* This function returns a pointer to the error_ptr associated with the user
+ * functions. The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_error_ptr(png_structp png_ptr)
+{
+ if (png_ptr == NULL)
+ return NULL;
+ return ((png_voidp)png_ptr->error_ptr);
+}
+
+
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+void PNGAPI
+png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
+{
+ if (png_ptr != NULL)
+ {
+ png_ptr->flags &=
+ ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
+ }
+}
+#endif
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
--- /dev/null
+
+/* pngget.c - retrieval of values from info struct
+ *
+ * Last changed in libpng 1.4.2 [May 6, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#include "pngpriv.h"
+
+png_uint_32 PNGAPI
+png_get_valid(png_structp png_ptr, png_infop info_ptr, png_uint_32 flag)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return(info_ptr->valid & flag);
+
+ else
+ return(0);
+}
+
+png_size_t PNGAPI
+png_get_rowbytes(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return(info_ptr->rowbytes);
+
+ else
+ return(0);
+}
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+png_bytepp PNGAPI
+png_get_rows(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return(info_ptr->row_pointers);
+
+ else
+ return(0);
+}
+#endif
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* Easy access to info, added in libpng-0.99 */
+png_uint_32 PNGAPI
+png_get_image_width(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->width;
+
+ return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_image_height(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->height;
+
+ return (0);
+}
+
+png_byte PNGAPI
+png_get_bit_depth(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->bit_depth;
+
+ return (0);
+}
+
+png_byte PNGAPI
+png_get_color_type(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->color_type;
+
+ return (0);
+}
+
+png_byte PNGAPI
+png_get_filter_type(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->filter_type;
+
+ return (0);
+}
+
+png_byte PNGAPI
+png_get_interlace_type(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->interlace_type;
+
+ return (0);
+}
+
+png_byte PNGAPI
+png_get_compression_type(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->compression_type;
+
+ return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_x_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+#ifdef PNG_pHYs_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_pHYs)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_x_pixels_per_meter");
+
+ if (info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
+ return (0);
+
+ else
+ return (info_ptr->x_pixels_per_unit);
+ }
+#else
+ return (0);
+#endif
+ return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_y_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+#ifdef PNG_pHYs_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_pHYs)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_y_pixels_per_meter");
+
+ if (info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
+ return (0);
+
+ else
+ return (info_ptr->y_pixels_per_unit);
+ }
+#else
+ return (0);
+#endif
+ return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+#ifdef PNG_pHYs_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_pHYs)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter");
+
+ if (info_ptr->phys_unit_type != PNG_RESOLUTION_METER ||
+ info_ptr->x_pixels_per_unit != info_ptr->y_pixels_per_unit)
+ return (0);
+
+ else
+ return (info_ptr->x_pixels_per_unit);
+ }
+#else
+ return (0);
+#endif
+ return (0);
+}
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_pixel_aspect_ratio(png_structp png_ptr, png_infop info_ptr)
+ {
+ if (png_ptr != NULL && info_ptr != NULL)
+#ifdef PNG_pHYs_SUPPORTED
+
+ if (info_ptr->valid & PNG_INFO_pHYs)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio");
+
+ if (info_ptr->x_pixels_per_unit == 0)
+ return ((float)0.0);
+
+ else
+ return ((float)((float)info_ptr->y_pixels_per_unit
+ /(float)info_ptr->x_pixels_per_unit));
+ }
+#else
+ return (0.0);
+#endif
+ return ((float)0.0);
+}
+#endif
+
+png_int_32 PNGAPI
+png_get_x_offset_microns(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+#ifdef PNG_oFFs_SUPPORTED
+
+ if (info_ptr->valid & PNG_INFO_oFFs)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns");
+
+ if (info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
+ return (0);
+
+ else
+ return (info_ptr->x_offset);
+ }
+#else
+ return (0);
+#endif
+ return (0);
+}
+
+png_int_32 PNGAPI
+png_get_y_offset_microns(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+
+#ifdef PNG_oFFs_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_oFFs)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns");
+
+ if (info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
+ return (0);
+
+ else
+ return (info_ptr->y_offset);
+ }
+#else
+ return (0);
+#endif
+ return (0);
+}
+
+png_int_32 PNGAPI
+png_get_x_offset_pixels(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+
+#ifdef PNG_oFFs_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_oFFs)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns");
+
+ if (info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
+ return (0);
+
+ else
+ return (info_ptr->x_offset);
+ }
+#else
+ return (0);
+#endif
+ return (0);
+}
+
+png_int_32 PNGAPI
+png_get_y_offset_pixels(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+
+#ifdef PNG_oFFs_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_oFFs)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns");
+
+ if (info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
+ return (0);
+
+ else
+ return (info_ptr->y_offset);
+ }
+#else
+ return (0);
+#endif
+ return (0);
+}
+
+#if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
+{
+ return ((png_uint_32)((float)png_get_pixels_per_meter(png_ptr, info_ptr)
+ *.0254 +.5));
+}
+
+png_uint_32 PNGAPI
+png_get_x_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
+{
+ return ((png_uint_32)((float)png_get_x_pixels_per_meter(png_ptr, info_ptr)
+ *.0254 +.5));
+}
+
+png_uint_32 PNGAPI
+png_get_y_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
+{
+ return ((png_uint_32)((float)png_get_y_pixels_per_meter(png_ptr, info_ptr)
+ *.0254 +.5));
+}
+
+float PNGAPI
+png_get_x_offset_inches(png_structp png_ptr, png_infop info_ptr)
+{
+ return ((float)png_get_x_offset_microns(png_ptr, info_ptr)
+ *.00003937);
+}
+
+float PNGAPI
+png_get_y_offset_inches(png_structp png_ptr, png_infop info_ptr)
+{
+ return ((float)png_get_y_offset_microns(png_ptr, info_ptr)
+ *.00003937);
+}
+
+#ifdef PNG_pHYs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pHYs_dpi(png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+ png_uint_32 retval = 0;
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+ {
+ png_debug1(1, "in %s retrieval function", "pHYs");
+
+ if (res_x != NULL)
+ {
+ *res_x = info_ptr->x_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+ if (res_y != NULL)
+ {
+ *res_y = info_ptr->y_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+ if (unit_type != NULL)
+ {
+ *unit_type = (int)info_ptr->phys_unit_type;
+ retval |= PNG_INFO_pHYs;
+ if (*unit_type == 1)
+ {
+ if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50);
+ if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
+ }
+ }
+ }
+ return (retval);
+}
+#endif /* PNG_pHYs_SUPPORTED */
+#endif /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
+
+/* png_get_channels really belongs in here, too, but it's been around longer */
+
+#endif /* PNG_EASY_ACCESS_SUPPORTED */
+
+png_byte PNGAPI
+png_get_channels(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return(info_ptr->channels);
+ else
+ return (0);
+}
+
+png_bytep PNGAPI
+png_get_signature(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return(info_ptr->signature);
+ else
+ return (NULL);
+}
+
+#ifdef PNG_bKGD_SUPPORTED
+png_uint_32 PNGAPI
+png_get_bKGD(png_structp png_ptr, png_infop info_ptr,
+ png_color_16p *background)
+{
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)
+ && background != NULL)
+ {
+ png_debug1(1, "in %s retrieval function", "bKGD");
+
+ *background = &(info_ptr->background);
+ return (PNG_INFO_bKGD);
+ }
+ return (0);
+}
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM(png_structp png_ptr, png_infop info_ptr,
+ double *white_x, double *white_y, double *red_x, double *red_y,
+ double *green_x, double *green_y, double *blue_x, double *blue_y)
+{
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+ {
+ png_debug1(1, "in %s retrieval function", "cHRM");
+
+ if (white_x != NULL)
+ *white_x = (double)info_ptr->x_white;
+ if (white_y != NULL)
+ *white_y = (double)info_ptr->y_white;
+ if (red_x != NULL)
+ *red_x = (double)info_ptr->x_red;
+ if (red_y != NULL)
+ *red_y = (double)info_ptr->y_red;
+ if (green_x != NULL)
+ *green_x = (double)info_ptr->x_green;
+ if (green_y != NULL)
+ *green_y = (double)info_ptr->y_green;
+ if (blue_x != NULL)
+ *blue_x = (double)info_ptr->x_blue;
+ if (blue_y != NULL)
+ *blue_y = (double)info_ptr->y_blue;
+ return (PNG_INFO_cHRM);
+ }
+ return (0);
+}
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM_fixed(png_structp png_ptr, png_infop info_ptr,
+ png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
+ png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
+ png_fixed_point *blue_x, png_fixed_point *blue_y)
+{
+ png_debug1(1, "in %s retrieval function", "cHRM");
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+ {
+ if (white_x != NULL)
+ *white_x = info_ptr->int_x_white;
+ if (white_y != NULL)
+ *white_y = info_ptr->int_y_white;
+ if (red_x != NULL)
+ *red_x = info_ptr->int_x_red;
+ if (red_y != NULL)
+ *red_y = info_ptr->int_y_red;
+ if (green_x != NULL)
+ *green_x = info_ptr->int_x_green;
+ if (green_y != NULL)
+ *green_y = info_ptr->int_y_green;
+ if (blue_x != NULL)
+ *blue_x = info_ptr->int_x_blue;
+ if (blue_y != NULL)
+ *blue_y = info_ptr->int_y_blue;
+ return (PNG_INFO_cHRM);
+ }
+ return (0);
+}
+#endif
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA(png_structp png_ptr, png_infop info_ptr, double *file_gamma)
+{
+ png_debug1(1, "in %s retrieval function", "gAMA");
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+ && file_gamma != NULL)
+ {
+ *file_gamma = (double)info_ptr->gamma;
+ return (PNG_INFO_gAMA);
+ }
+ return (0);
+}
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA_fixed(png_structp png_ptr, png_infop info_ptr,
+ png_fixed_point *int_file_gamma)
+{
+ png_debug1(1, "in %s retrieval function", "gAMA");
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+ && int_file_gamma != NULL)
+ {
+ *int_file_gamma = info_ptr->int_gamma;
+ return (PNG_INFO_gAMA);
+ }
+ return (0);
+}
+#endif
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sRGB(png_structp png_ptr, png_infop info_ptr, int *file_srgb_intent)
+{
+ png_debug1(1, "in %s retrieval function", "sRGB");
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)
+ && file_srgb_intent != NULL)
+ {
+ *file_srgb_intent = (int)info_ptr->srgb_intent;
+ return (PNG_INFO_sRGB);
+ }
+ return (0);
+}
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+png_uint_32 PNGAPI
+png_get_iCCP(png_structp png_ptr, png_infop info_ptr,
+ png_charpp name, int *compression_type,
+ png_charpp profile, png_uint_32 *proflen)
+{
+ png_debug1(1, "in %s retrieval function", "iCCP");
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)
+ && name != NULL && profile != NULL && proflen != NULL)
+ {
+ *name = info_ptr->iccp_name;
+ *profile = info_ptr->iccp_profile;
+ /* Compression_type is a dummy so the API won't have to change
+ * if we introduce multiple compression types later.
+ */
+ *proflen = (int)info_ptr->iccp_proflen;
+ *compression_type = (int)info_ptr->iccp_compression;
+ return (PNG_INFO_iCCP);
+ }
+ return (0);
+}
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sPLT(png_structp png_ptr, png_infop info_ptr,
+ png_sPLT_tpp spalettes)
+{
+ if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
+ {
+ *spalettes = info_ptr->splt_palettes;
+ return ((png_uint_32)info_ptr->splt_palettes_num);
+ }
+ return (0);
+}
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+png_uint_32 PNGAPI
+png_get_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p *hist)
+{
+ png_debug1(1, "in %s retrieval function", "hIST");
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)
+ && hist != NULL)
+ {
+ *hist = info_ptr->hist;
+ return (PNG_INFO_hIST);
+ }
+ return (0);
+}
+#endif
+
+png_uint_32 PNGAPI
+png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 *width, png_uint_32 *height, int *bit_depth,
+ int *color_type, int *interlace_type, int *compression_type,
+ int *filter_type)
+
+{
+ png_debug1(1, "in %s retrieval function", "IHDR");
+
+ if (png_ptr == NULL || info_ptr == NULL || width == NULL ||
+ height == NULL || bit_depth == NULL || color_type == NULL)
+ return (0);
+
+ *width = info_ptr->width;
+ *height = info_ptr->height;
+ *bit_depth = info_ptr->bit_depth;
+ *color_type = info_ptr->color_type;
+
+ if (compression_type != NULL)
+ *compression_type = info_ptr->compression_type;
+
+ if (filter_type != NULL)
+ *filter_type = info_ptr->filter_type;
+
+ if (interlace_type != NULL)
+ *interlace_type = info_ptr->interlace_type;
+
+ /* This is redundant if we can be sure that the info_ptr values were all
+ * assigned in png_set_IHDR(). We do the check anyhow in case an
+ * application has ignored our advice not to mess with the members
+ * of info_ptr directly.
+ */
+ png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+ info_ptr->compression_type, info_ptr->filter_type);
+
+ return (1);
+}
+
+#ifdef PNG_oFFs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_oFFs(png_structp png_ptr, png_infop info_ptr,
+ png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
+{
+ png_debug1(1, "in %s retrieval function", "oFFs");
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)
+ && offset_x != NULL && offset_y != NULL && unit_type != NULL)
+ {
+ *offset_x = info_ptr->x_offset;
+ *offset_y = info_ptr->y_offset;
+ *unit_type = (int)info_ptr->offset_unit_type;
+ return (PNG_INFO_oFFs);
+ }
+ return (0);
+}
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pCAL(png_structp png_ptr, png_infop info_ptr,
+ png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
+ png_charp *units, png_charpp *params)
+{
+ png_debug1(1, "in %s retrieval function", "pCAL");
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)
+ && purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
+ nparams != NULL && units != NULL && params != NULL)
+ {
+ *purpose = info_ptr->pcal_purpose;
+ *X0 = info_ptr->pcal_X0;
+ *X1 = info_ptr->pcal_X1;
+ *type = (int)info_ptr->pcal_type;
+ *nparams = (int)info_ptr->pcal_nparams;
+ *units = info_ptr->pcal_units;
+ *params = info_ptr->pcal_params;
+ return (PNG_INFO_pCAL);
+ }
+ return (0);
+}
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sCAL(png_structp png_ptr, png_infop info_ptr,
+ int *unit, double *width, double *height)
+{
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sCAL))
+ {
+ *unit = info_ptr->scal_unit;
+ *width = info_ptr->scal_pixel_width;
+ *height = info_ptr->scal_pixel_height;
+ return (PNG_INFO_sCAL);
+ }
+ return(0);
+}
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sCAL_s(png_structp png_ptr, png_infop info_ptr,
+ int *unit, png_charpp width, png_charpp height)
+{
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sCAL))
+ {
+ *unit = info_ptr->scal_unit;
+ *width = info_ptr->scal_s_width;
+ *height = info_ptr->scal_s_height;
+ return (PNG_INFO_sCAL);
+ }
+ return(0);
+}
+#endif
+#endif
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pHYs(png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+ png_uint_32 retval = 0;
+
+ png_debug1(1, "in %s retrieval function", "pHYs");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs))
+ {
+ if (res_x != NULL)
+ {
+ *res_x = info_ptr->x_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+
+ if (res_y != NULL)
+ {
+ *res_y = info_ptr->y_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+
+ if (unit_type != NULL)
+ {
+ *unit_type = (int)info_ptr->phys_unit_type;
+ retval |= PNG_INFO_pHYs;
+ }
+ }
+ return (retval);
+}
+#endif
+
+png_uint_32 PNGAPI
+png_get_PLTE(png_structp png_ptr, png_infop info_ptr, png_colorp *palette,
+ int *num_palette)
+{
+ png_debug1(1, "in %s retrieval function", "PLTE");
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_PLTE)
+ && palette != NULL)
+ {
+ *palette = info_ptr->palette;
+ *num_palette = info_ptr->num_palette;
+ png_debug1(3, "num_palette = %d", *num_palette);
+ return (PNG_INFO_PLTE);
+ }
+ return (0);
+}
+
+#ifdef PNG_sBIT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sBIT(png_structp png_ptr, png_infop info_ptr, png_color_8p *sig_bit)
+{
+ png_debug1(1, "in %s retrieval function", "sBIT");
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)
+ && sig_bit != NULL)
+ {
+ *sig_bit = &(info_ptr->sig_bit);
+ return (PNG_INFO_sBIT);
+ }
+ return (0);
+}
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_text(png_structp png_ptr, png_infop info_ptr, png_textp *text_ptr,
+ int *num_text)
+{
+ if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
+ {
+ png_debug1(1, "in %s retrieval function",
+ (png_ptr->chunk_name[0] == '\0' ? "text"
+ : (png_const_charp)png_ptr->chunk_name));
+
+ if (text_ptr != NULL)
+ *text_ptr = info_ptr->text;
+
+ if (num_text != NULL)
+ *num_text = info_ptr->num_text;
+
+ return ((png_uint_32)info_ptr->num_text);
+ }
+ if (num_text != NULL)
+ *num_text = 0;
+ return(0);
+}
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+png_uint_32 PNGAPI
+png_get_tIME(png_structp png_ptr, png_infop info_ptr, png_timep *mod_time)
+{
+ png_debug1(1, "in %s retrieval function", "tIME");
+
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)
+ && mod_time != NULL)
+ {
+ *mod_time = &(info_ptr->mod_time);
+ return (PNG_INFO_tIME);
+ }
+ return (0);
+}
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+png_uint_32 PNGAPI
+png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
+ png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
+{
+ png_uint_32 retval = 0;
+ if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+ {
+ png_debug1(1, "in %s retrieval function", "tRNS");
+
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (trans_alpha != NULL)
+ {
+ *trans_alpha = info_ptr->trans_alpha;
+ retval |= PNG_INFO_tRNS;
+ }
+
+ if (trans_color != NULL)
+ *trans_color = &(info_ptr->trans_color);
+ }
+ else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */
+ {
+ if (trans_color != NULL)
+ {
+ *trans_color = &(info_ptr->trans_color);
+ retval |= PNG_INFO_tRNS;
+ }
+
+ if (trans_alpha != NULL)
+ *trans_alpha = NULL;
+ }
+ if (num_trans != NULL)
+ {
+ *num_trans = info_ptr->num_trans;
+ retval |= PNG_INFO_tRNS;
+ }
+ }
+ return (retval);
+}
+#endif
+
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+png_uint_32 PNGAPI
+png_get_unknown_chunks(png_structp png_ptr, png_infop info_ptr,
+ png_unknown_chunkpp unknowns)
+{
+ if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
+ {
+ *unknowns = info_ptr->unknown_chunks;
+ return ((png_uint_32)info_ptr->unknown_chunks_num);
+ }
+ return (0);
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+png_byte PNGAPI
+png_get_rgb_to_gray_status (png_structp png_ptr)
+{
+ return (png_byte)(png_ptr? png_ptr->rgb_to_gray_status : 0);
+}
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+png_voidp PNGAPI
+png_get_user_chunk_ptr(png_structp png_ptr)
+{
+ return (png_ptr? png_ptr->user_chunk_ptr : NULL);
+}
+#endif
+
+png_size_t PNGAPI
+png_get_compression_buffer_size(png_structp png_ptr)
+{
+ return (png_ptr ? png_ptr->zbuf_size : 0L);
+}
+
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* These functions were added to libpng 1.2.6 and were enabled
+ * by default in libpng-1.4.0 */
+png_uint_32 PNGAPI
+png_get_user_width_max (png_structp png_ptr)
+{
+ return (png_ptr? png_ptr->user_width_max : 0);
+}
+png_uint_32 PNGAPI
+png_get_user_height_max (png_structp png_ptr)
+{
+ return (png_ptr? png_ptr->user_height_max : 0);
+}
+/* This function was added to libpng 1.4.0 */
+png_uint_32 PNGAPI
+png_get_chunk_cache_max (png_structp png_ptr)
+{
+ return (png_ptr? png_ptr->user_chunk_cache_max : 0);
+}
+/* This function was added to libpng 1.4.1 */
+png_alloc_size_t PNGAPI
+png_get_chunk_malloc_max (png_structp png_ptr)
+{
+ return (png_ptr?
+ png_ptr->user_chunk_malloc_max : 0);
+}
+#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
+
+/* These functions were added to libpng 1.4.0 */
+#ifdef PNG_IO_STATE_SUPPORTED
+png_uint_32 PNGAPI
+png_get_io_state (png_structp png_ptr)
+{
+ return png_ptr->io_state;
+}
+
+png_bytep PNGAPI
+png_get_io_chunk_name (png_structp png_ptr)
+{
+ return png_ptr->chunk_name;
+}
+#endif /* ?PNG_IO_STATE_SUPPORTED */
+
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
--- /dev/null
+
+/* pngmem.c - stub functions for memory allocation
+ *
+ * Last changed in libpng 1.4.2 [May 6, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all memory allocation. Users who
+ * need special memory handling are expected to supply replacement
+ * functions for png_malloc() and png_free(), and to use
+ * png_create_read_struct_2() and png_create_write_struct_2() to
+ * identify the replacement functions.
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#include "pngpriv.h"
+
+/* Borland DOS special memory handler */
+#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
+/* If you change this, be sure to change the one in png.h also */
+
+/* Allocate memory for a png_struct. The malloc and memset can be replaced
+ by a single call to calloc() if this is thought to improve performance. */
+png_voidp /* PRIVATE */
+png_create_struct(int type)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+ return (png_create_struct_2(type, NULL, NULL));
+}
+
+/* Alternate version of png_create_struct, for use with user-defined malloc. */
+png_voidp /* PRIVATE */
+png_create_struct_2(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+ png_size_t size;
+ png_voidp struct_ptr;
+
+ if (type == PNG_STRUCT_INFO)
+ size = png_sizeof(png_info);
+ else if (type == PNG_STRUCT_PNG)
+ size = png_sizeof(png_struct);
+ else
+ return (png_get_copyright(NULL));
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (malloc_fn != NULL)
+ {
+ png_struct dummy_struct;
+ png_structp png_ptr = &dummy_struct;
+ png_ptr->mem_ptr=mem_ptr;
+ struct_ptr = (*(malloc_fn))(png_ptr, (png_uint_32)size);
+ }
+ else
+#endif /* PNG_USER_MEM_SUPPORTED */
+ struct_ptr = (png_voidp)farmalloc(size);
+ if (struct_ptr != NULL)
+ png_memset(struct_ptr, 0, size);
+ return (struct_ptr);
+}
+
+/* Free memory allocated by a png_create_struct() call */
+void /* PRIVATE */
+png_destroy_struct(png_voidp struct_ptr)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2(struct_ptr, NULL, NULL);
+}
+
+/* Free memory allocated by a png_create_struct() call */
+void /* PRIVATE */
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
+ png_voidp mem_ptr)
+{
+#endif
+ if (struct_ptr != NULL)
+ {
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (free_fn != NULL)
+ {
+ png_struct dummy_struct;
+ png_structp png_ptr = &dummy_struct;
+ png_ptr->mem_ptr=mem_ptr;
+ (*(free_fn))(png_ptr, struct_ptr);
+ return;
+ }
+#endif /* PNG_USER_MEM_SUPPORTED */
+ farfree (struct_ptr);
+ }
+}
+
+/* Allocate memory. For reasonable files, size should never exceed
+ * 64K. However, zlib may allocate more then 64K if you don't tell
+ * it not to. See zconf.h and png.h for more information. zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ *
+ * Borland seems to have a problem in DOS mode for exactly 64K.
+ * It gives you a segment with an offset of 8 (perhaps to store its
+ * memory stuff). zlib doesn't like this at all, so we have to
+ * detect and deal with it. This code should not be needed in
+ * Windows or OS/2 modes, and only in 16 bit mode. This code has
+ * been updated by Alexander Lehmann for version 0.89 to waste less
+ * memory.
+ *
+ * Note that we can't use png_size_t for the "size" declaration,
+ * since on some systems a png_size_t is a 16-bit quantity, and as a
+ * result, we would be truncating potentially larger memory requests
+ * (which should cause a fatal error) and introducing major problems.
+ */
+png_voidp PNGAPI
+png_calloc(png_structp png_ptr, png_alloc_size_t size)
+{
+ png_voidp ret;
+
+ ret = (png_malloc(png_ptr, size));
+ if (ret != NULL)
+ png_memset(ret,0,(png_size_t)size);
+ return (ret);
+}
+
+png_voidp PNGAPI
+png_malloc(png_structp png_ptr, png_alloc_size_t size)
+{
+ png_voidp ret;
+
+ if (png_ptr == NULL || size == 0)
+ return (NULL);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (png_ptr->malloc_fn != NULL)
+ ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
+ else
+ ret = (png_malloc_default(png_ptr, size));
+ if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+ png_error(png_ptr, "Out of memory");
+ return (ret);
+}
+
+png_voidp PNGAPI
+png_malloc_default(png_structp png_ptr, png_alloc_size_t size)
+{
+ png_voidp ret;
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+ if (png_ptr == NULL || size == 0)
+ return (NULL);
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (size > (png_uint_32)65536L)
+ {
+ png_warning(png_ptr, "Cannot Allocate > 64K");
+ ret = NULL;
+ }
+ else
+#endif
+
+ if (size != (size_t)size)
+ ret = NULL;
+ else if (size == (png_uint_32)65536L)
+ {
+ if (png_ptr->offset_table == NULL)
+ {
+ /* Try to see if we need to do any of this fancy stuff */
+ ret = farmalloc(size);
+ if (ret == NULL || ((png_size_t)ret & 0xffff))
+ {
+ int num_blocks;
+ png_uint_32 total_size;
+ png_bytep table;
+ int i;
+ png_byte huge * hptr;
+
+ if (ret != NULL)
+ {
+ farfree(ret);
+ ret = NULL;
+ }
+
+ if (png_ptr->zlib_window_bits > 14)
+ num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
+ else
+ num_blocks = 1;
+ if (png_ptr->zlib_mem_level >= 7)
+ num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7));
+ else
+ num_blocks++;
+
+ total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16;
+
+ table = farmalloc(total_size);
+
+ if (table == NULL)
+ {
+#ifndef PNG_USER_MEM_SUPPORTED
+ if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+ png_error(png_ptr, "Out Of Memory"); /* Note "O", "M" */
+ else
+ png_warning(png_ptr, "Out Of Memory");
+#endif
+ return (NULL);
+ }
+
+ if ((png_size_t)table & 0xfff0)
+ {
+#ifndef PNG_USER_MEM_SUPPORTED
+ if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+ png_error(png_ptr,
+ "Farmalloc didn't return normalized pointer");
+ else
+ png_warning(png_ptr,
+ "Farmalloc didn't return normalized pointer");
+#endif
+ return (NULL);
+ }
+
+ png_ptr->offset_table = table;
+ png_ptr->offset_table_ptr = farmalloc(num_blocks *
+ png_sizeof(png_bytep));
+
+ if (png_ptr->offset_table_ptr == NULL)
+ {
+#ifndef PNG_USER_MEM_SUPPORTED
+ if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+ png_error(png_ptr, "Out Of memory"); /* Note "O", "m" */
+ else
+ png_warning(png_ptr, "Out Of memory");
+#endif
+ return (NULL);
+ }
+
+ hptr = (png_byte huge *)table;
+ if ((png_size_t)hptr & 0xf)
+ {
+ hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
+ hptr = hptr + 16L; /* "hptr += 16L" fails on Turbo C++ 3.0 */
+ }
+ for (i = 0; i < num_blocks; i++)
+ {
+ png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
+ hptr = hptr + (png_uint_32)65536L; /* "+=" fails on TC++3.0 */
+ }
+
+ png_ptr->offset_table_number = num_blocks;
+ png_ptr->offset_table_count = 0;
+ png_ptr->offset_table_count_free = 0;
+ }
+ }
+
+ if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
+ {
+#ifndef PNG_USER_MEM_SUPPORTED
+ if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+ png_error(png_ptr, "Out of Memory"); /* Note "o" and "M" */
+ else
+ png_warning(png_ptr, "Out of Memory");
+#endif
+ return (NULL);
+ }
+
+ ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
+ }
+ else
+ ret = farmalloc(size);
+
+#ifndef PNG_USER_MEM_SUPPORTED
+ if (ret == NULL)
+ {
+ if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+ png_error(png_ptr, "Out of memory"); /* Note "o" and "m" */
+ else
+ png_warning(png_ptr, "Out of memory"); /* Note "o" and "m" */
+ }
+#endif
+
+ return (ret);
+}
+
+/* Free a pointer allocated by png_malloc(). In the default
+ * configuration, png_ptr is not used, but is passed in case it
+ * is needed. If ptr is NULL, return without taking any action.
+ */
+void PNGAPI
+png_free(png_structp png_ptr, png_voidp ptr)
+{
+ if (png_ptr == NULL || ptr == NULL)
+ return;
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (png_ptr->free_fn != NULL)
+ {
+ (*(png_ptr->free_fn))(png_ptr, ptr);
+ return;
+ }
+ else
+ png_free_default(png_ptr, ptr);
+}
+
+void PNGAPI
+png_free_default(png_structp png_ptr, png_voidp ptr)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+ if (png_ptr == NULL || ptr == NULL)
+ return;
+
+ if (png_ptr->offset_table != NULL)
+ {
+ int i;
+
+ for (i = 0; i < png_ptr->offset_table_count; i++)
+ {
+ if (ptr == png_ptr->offset_table_ptr[i])
+ {
+ ptr = NULL;
+ png_ptr->offset_table_count_free++;
+ break;
+ }
+ }
+ if (png_ptr->offset_table_count_free == png_ptr->offset_table_count)
+ {
+ farfree(png_ptr->offset_table);
+ farfree(png_ptr->offset_table_ptr);
+ png_ptr->offset_table = NULL;
+ png_ptr->offset_table_ptr = NULL;
+ }
+ }
+
+ if (ptr != NULL)
+ {
+ farfree(ptr);
+ }
+}
+
+#else /* Not the Borland DOS special memory handler */
+
+/* Allocate memory for a png_struct or a png_info. The malloc and
+ memset can be replaced by a single call to calloc() if this is thought
+ to improve performance noticably. */
+png_voidp /* PRIVATE */
+png_create_struct(int type)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+ return (png_create_struct_2(type, NULL, NULL));
+}
+
+/* Allocate memory for a png_struct or a png_info. The malloc and
+ memset can be replaced by a single call to calloc() if this is thought
+ to improve performance noticably. */
+png_voidp /* PRIVATE */
+png_create_struct_2(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+ png_size_t size;
+ png_voidp struct_ptr;
+
+ if (type == PNG_STRUCT_INFO)
+ size = png_sizeof(png_info);
+ else if (type == PNG_STRUCT_PNG)
+ size = png_sizeof(png_struct);
+ else
+ return (NULL);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (malloc_fn != NULL)
+ {
+ png_struct dummy_struct;
+ png_structp png_ptr = &dummy_struct;
+ png_ptr->mem_ptr=mem_ptr;
+ struct_ptr = (*(malloc_fn))(png_ptr, size);
+ if (struct_ptr != NULL)
+ png_memset(struct_ptr, 0, size);
+ return (struct_ptr);
+ }
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+#if defined(__TURBOC__) && !defined(__FLAT__)
+ struct_ptr = (png_voidp)farmalloc(size);
+#else
+# if defined(_MSC_VER) && defined(MAXSEG_64K)
+ struct_ptr = (png_voidp)halloc(size, 1);
+# else
+ struct_ptr = (png_voidp)malloc(size);
+# endif
+#endif
+ if (struct_ptr != NULL)
+ png_memset(struct_ptr, 0, size);
+
+ return (struct_ptr);
+}
+
+
+/* Free memory allocated by a png_create_struct() call */
+void /* PRIVATE */
+png_destroy_struct(png_voidp struct_ptr)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2(struct_ptr, NULL, NULL);
+}
+
+/* Free memory allocated by a png_create_struct() call */
+void /* PRIVATE */
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
+ png_voidp mem_ptr)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+ if (struct_ptr != NULL)
+ {
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (free_fn != NULL)
+ {
+ png_struct dummy_struct;
+ png_structp png_ptr = &dummy_struct;
+ png_ptr->mem_ptr=mem_ptr;
+ (*(free_fn))(png_ptr, struct_ptr);
+ return;
+ }
+#endif /* PNG_USER_MEM_SUPPORTED */
+#if defined(__TURBOC__) && !defined(__FLAT__)
+ farfree(struct_ptr);
+#else
+# if defined(_MSC_VER) && defined(MAXSEG_64K)
+ hfree(struct_ptr);
+# else
+ free(struct_ptr);
+# endif
+#endif
+ }
+}
+
+/* Allocate memory. For reasonable files, size should never exceed
+ * 64K. However, zlib may allocate more then 64K if you don't tell
+ * it not to. See zconf.h and png.h for more information. zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ */
+
+png_voidp PNGAPI
+png_calloc(png_structp png_ptr, png_alloc_size_t size)
+{
+ png_voidp ret;
+
+ ret = (png_malloc(png_ptr, size));
+ if (ret != NULL)
+ png_memset(ret,0,(png_size_t)size);
+ return (ret);
+}
+
+png_voidp PNGAPI
+png_malloc(png_structp png_ptr, png_alloc_size_t size)
+{
+ png_voidp ret;
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (png_ptr == NULL || size == 0)
+ return (NULL);
+
+ if (png_ptr->malloc_fn != NULL)
+ ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
+ else
+ ret = (png_malloc_default(png_ptr, size));
+ if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+ png_error(png_ptr, "Out of Memory");
+ return (ret);
+}
+
+png_voidp PNGAPI
+png_malloc_default(png_structp png_ptr, png_alloc_size_t size)
+{
+ png_voidp ret;
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+ if (png_ptr == NULL || size == 0)
+ return (NULL);
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (size > (png_uint_32)65536L)
+ {
+#ifndef PNG_USER_MEM_SUPPORTED
+ if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+ png_error(png_ptr, "Cannot Allocate > 64K");
+ else
+#endif
+ return NULL;
+ }
+#endif
+
+ /* Check for overflow */
+#if defined(__TURBOC__) && !defined(__FLAT__)
+ if (size != (unsigned long)size)
+ ret = NULL;
+ else
+ ret = farmalloc(size);
+#else
+# if defined(_MSC_VER) && defined(MAXSEG_64K)
+ if (size != (unsigned long)size)
+ ret = NULL;
+ else
+ ret = halloc(size, 1);
+# else
+ if (size != (size_t)size)
+ ret = NULL;
+ else
+ ret = malloc((size_t)size);
+# endif
+#endif
+
+#ifndef PNG_USER_MEM_SUPPORTED
+ if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+ png_error(png_ptr, "Out of Memory");
+#endif
+
+ return (ret);
+}
+
+/* Free a pointer allocated by png_malloc(). If ptr is NULL, return
+ * without taking any action.
+ */
+void PNGAPI
+png_free(png_structp png_ptr, png_voidp ptr)
+{
+ if (png_ptr == NULL || ptr == NULL)
+ return;
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (png_ptr->free_fn != NULL)
+ {
+ (*(png_ptr->free_fn))(png_ptr, ptr);
+ return;
+ }
+ else
+ png_free_default(png_ptr, ptr);
+}
+void PNGAPI
+png_free_default(png_structp png_ptr, png_voidp ptr)
+{
+ if (png_ptr == NULL || ptr == NULL)
+ return;
+
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+#if defined(__TURBOC__) && !defined(__FLAT__)
+ farfree(ptr);
+#else
+# if defined(_MSC_VER) && defined(MAXSEG_64K)
+ hfree(ptr);
+# else
+ free(ptr);
+# endif
+#endif
+}
+
+#endif /* Not Borland DOS special memory handler */
+
+/* This function was added at libpng version 1.2.3. The png_malloc_warn()
+ * function will set up png_malloc() to issue a png_warning and return NULL
+ * instead of issuing a png_error, if it fails to allocate the requested
+ * memory.
+ */
+png_voidp PNGAPI
+png_malloc_warn(png_structp png_ptr, png_alloc_size_t size)
+{
+ png_voidp ptr;
+ png_uint_32 save_flags;
+ if (png_ptr == NULL)
+ return (NULL);
+
+ save_flags = png_ptr->flags;
+ png_ptr->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
+ ptr = (png_voidp)png_malloc((png_structp)png_ptr, size);
+ png_ptr->flags=save_flags;
+ return(ptr);
+}
+
+
+#ifdef PNG_USER_MEM_SUPPORTED
+/* This function is called when the application wants to use another method
+ * of allocating and freeing memory.
+ */
+void PNGAPI
+png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
+ malloc_fn, png_free_ptr free_fn)
+{
+ if (png_ptr != NULL)
+ {
+ png_ptr->mem_ptr = mem_ptr;
+ png_ptr->malloc_fn = malloc_fn;
+ png_ptr->free_fn = free_fn;
+ }
+}
+
+/* This function returns a pointer to the mem_ptr associated with the user
+ * functions. The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_mem_ptr(png_structp png_ptr)
+{
+ if (png_ptr == NULL)
+ return (NULL);
+ return ((png_voidp)png_ptr->mem_ptr);
+}
+#endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
--- /dev/null
+
+/* pngpread.c - read a png file in push mode
+ *
+ * Last changed in libpng 1.4.3 [June 26, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+#include "pngpriv.h"
+
+/* Push model modes */
+#define PNG_READ_SIG_MODE 0
+#define PNG_READ_CHUNK_MODE 1
+#define PNG_READ_IDAT_MODE 2
+#define PNG_SKIP_MODE 3
+#define PNG_READ_tEXt_MODE 4
+#define PNG_READ_zTXt_MODE 5
+#define PNG_READ_DONE_MODE 6
+#define PNG_READ_iTXt_MODE 7
+#define PNG_ERROR_MODE 8
+
+void PNGAPI
+png_process_data(png_structp png_ptr, png_infop info_ptr,
+ png_bytep buffer, png_size_t buffer_size)
+{
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_push_restore_buffer(png_ptr, buffer, buffer_size);
+
+ while (png_ptr->buffer_size)
+ {
+ png_process_some_data(png_ptr, info_ptr);
+ }
+}
+
+/* What we do with the incoming data depends on what we were previously
+ * doing before we ran out of data...
+ */
+void /* PRIVATE */
+png_process_some_data(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr == NULL)
+ return;
+
+ switch (png_ptr->process_mode)
+ {
+ case PNG_READ_SIG_MODE:
+ {
+ png_push_read_sig(png_ptr, info_ptr);
+ break;
+ }
+
+ case PNG_READ_CHUNK_MODE:
+ {
+ png_push_read_chunk(png_ptr, info_ptr);
+ break;
+ }
+
+ case PNG_READ_IDAT_MODE:
+ {
+ png_push_read_IDAT(png_ptr);
+ break;
+ }
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+ case PNG_READ_tEXt_MODE:
+ {
+ png_push_read_tEXt(png_ptr, info_ptr);
+ break;
+ }
+
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+ case PNG_READ_zTXt_MODE:
+ {
+ png_push_read_zTXt(png_ptr, info_ptr);
+ break;
+ }
+
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+ case PNG_READ_iTXt_MODE:
+ {
+ png_push_read_iTXt(png_ptr, info_ptr);
+ break;
+ }
+
+#endif
+ case PNG_SKIP_MODE:
+ {
+ png_push_crc_finish(png_ptr);
+ break;
+ }
+
+ default:
+ {
+ png_ptr->buffer_size = 0;
+ break;
+ }
+ }
+}
+
+/* Read any remaining signature bytes from the stream and compare them with
+ * the correct PNG signature. It is possible that this routine is called
+ * with bytes already read from the signature, either because they have been
+ * checked by the calling application, or because of multiple calls to this
+ * routine.
+ */
+void /* PRIVATE */
+png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
+{
+ png_size_t num_checked = png_ptr->sig_bytes,
+ num_to_check = 8 - num_checked;
+
+ if (png_ptr->buffer_size < num_to_check)
+ {
+ num_to_check = png_ptr->buffer_size;
+ }
+
+ png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
+ num_to_check);
+ png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
+
+ if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
+ {
+ if (num_checked < 4 &&
+ png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+ png_error(png_ptr, "Not a PNG file");
+ else
+ png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+ }
+ else
+ {
+ if (png_ptr->sig_bytes >= 8)
+ {
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+ }
+ }
+}
+
+void /* PRIVATE */
+png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
+{
+ PNG_IHDR;
+ PNG_IDAT;
+ PNG_IEND;
+ PNG_PLTE;
+#ifdef PNG_READ_bKGD_SUPPORTED
+ PNG_bKGD;
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+ PNG_cHRM;
+#endif
+#ifdef PNG_READ_gAMA_SUPPORTED
+ PNG_gAMA;
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+ PNG_hIST;
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+ PNG_iCCP;
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+ PNG_iTXt;
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+ PNG_oFFs;
+#endif
+#ifdef PNG_READ_pCAL_SUPPORTED
+ PNG_pCAL;
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+ PNG_pHYs;
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+ PNG_sBIT;
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+ PNG_sCAL;
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+ PNG_sRGB;
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+ PNG_sPLT;
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+ PNG_tEXt;
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+ PNG_tIME;
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+ PNG_tRNS;
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+ PNG_zTXt;
+#endif
+
+ /* First we make sure we have enough data for the 4 byte chunk name
+ * and the 4 byte chunk length before proceeding with decoding the
+ * chunk data. To fully decode each of these chunks, we also make
+ * sure we have enough data in the buffer for the 4 byte CRC at the
+ * end of every chunk (except IDAT, which is handled separately).
+ */
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
+ {
+ png_byte chunk_length[4];
+
+ if (png_ptr->buffer_size < 8)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_fill_buffer(png_ptr, chunk_length, 4);
+ png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
+ png_reset_crc(png_ptr);
+ png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+ png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+ }
+
+ if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ if (png_ptr->mode & PNG_AFTER_IDAT)
+ png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+ if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
+ {
+ if (png_ptr->push_length != 13)
+ png_error(png_ptr, "Invalid IHDR length");
+
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+ else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
+
+ png_ptr->process_mode = PNG_READ_DONE_MODE;
+ png_push_have_end(png_ptr, info_ptr);
+ }
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ png_ptr->mode |= PNG_HAVE_IDAT;
+
+ png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+
+ if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+ png_ptr->mode |= PNG_HAVE_PLTE;
+
+ else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ {
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before IDAT");
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ !(png_ptr->mode & PNG_HAVE_PLTE))
+ png_error(png_ptr, "Missing PLTE before IDAT");
+ }
+ }
+
+#endif
+ else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+ else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ {
+ /* If we reach an IDAT chunk, this means we have read all of the
+ * header chunks, and we can start reading the image (or if this
+ * is called after the image has been read - we have an error).
+ */
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before IDAT");
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ !(png_ptr->mode & PNG_HAVE_PLTE))
+ png_error(png_ptr, "Missing PLTE before IDAT");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+ if (png_ptr->push_length == 0)
+ return;
+
+ if (png_ptr->mode & PNG_AFTER_IDAT)
+ png_benign_error(png_ptr, "Too many IDATs found");
+ }
+
+ png_ptr->idat_size = png_ptr->push_length;
+ png_ptr->mode |= PNG_HAVE_IDAT;
+ png_ptr->process_mode = PNG_READ_IDAT_MODE;
+ png_push_have_info(png_ptr, info_ptr);
+ png_ptr->zstream.avail_out =
+ (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
+ png_ptr->iwidth) + 1;
+ png_ptr->zstream.next_out = png_ptr->row_buf;
+ return;
+ }
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_bKGD_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+ else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+ else
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+}
+
+void /* PRIVATE */
+png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
+{
+ png_ptr->process_mode = PNG_SKIP_MODE;
+ png_ptr->skip_length = skip;
+}
+
+void /* PRIVATE */
+png_push_crc_finish(png_structp png_ptr)
+{
+ if (png_ptr->skip_length && png_ptr->save_buffer_size)
+ {
+ png_size_t save_size;
+
+ if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
+ save_size = (png_size_t)png_ptr->skip_length;
+ else
+ save_size = png_ptr->save_buffer_size;
+
+ png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
+
+ png_ptr->skip_length -= save_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->save_buffer_size -= save_size;
+ png_ptr->save_buffer_ptr += save_size;
+ }
+ if (png_ptr->skip_length && png_ptr->current_buffer_size)
+ {
+ png_size_t save_size;
+
+ if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
+ save_size = (png_size_t)png_ptr->skip_length;
+ else
+ save_size = png_ptr->current_buffer_size;
+
+ png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
+
+ png_ptr->skip_length -= save_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->current_buffer_size -= save_size;
+ png_ptr->current_buffer_ptr += save_size;
+ }
+ if (!png_ptr->skip_length)
+ {
+ if (png_ptr->buffer_size < 4)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_crc_finish(png_ptr, 0);
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+ }
+}
+
+void PNGAPI
+png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
+{
+ png_bytep ptr;
+
+ if (png_ptr == NULL)
+ return;
+
+ ptr = buffer;
+ if (png_ptr->save_buffer_size)
+ {
+ png_size_t save_size;
+
+ if (length < png_ptr->save_buffer_size)
+ save_size = length;
+ else
+ save_size = png_ptr->save_buffer_size;
+
+ png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
+ length -= save_size;
+ ptr += save_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->save_buffer_size -= save_size;
+ png_ptr->save_buffer_ptr += save_size;
+ }
+ if (length && png_ptr->current_buffer_size)
+ {
+ png_size_t save_size;
+
+ if (length < png_ptr->current_buffer_size)
+ save_size = length;
+
+ else
+ save_size = png_ptr->current_buffer_size;
+
+ png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
+ png_ptr->buffer_size -= save_size;
+ png_ptr->current_buffer_size -= save_size;
+ png_ptr->current_buffer_ptr += save_size;
+ }
+}
+
+void /* PRIVATE */
+png_push_save_buffer(png_structp png_ptr)
+{
+ if (png_ptr->save_buffer_size)
+ {
+ if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
+ {
+ png_size_t i, istop;
+ png_bytep sp;
+ png_bytep dp;
+
+ istop = png_ptr->save_buffer_size;
+ for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
+ i < istop; i++, sp++, dp++)
+ {
+ *dp = *sp;
+ }
+ }
+ }
+ if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
+ png_ptr->save_buffer_max)
+ {
+ png_size_t new_max;
+ png_bytep old_buffer;
+
+ if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
+ (png_ptr->current_buffer_size + 256))
+ {
+ png_error(png_ptr, "Potential overflow of save_buffer");
+ }
+
+ new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
+ old_buffer = png_ptr->save_buffer;
+ png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr,
+ (png_size_t)new_max);
+ if (png_ptr->save_buffer == NULL)
+ {
+ png_free(png_ptr, old_buffer);
+ png_error(png_ptr, "Insufficient memory for save_buffer");
+ }
+ png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
+ png_free(png_ptr, old_buffer);
+ png_ptr->save_buffer_max = new_max;
+ }
+ if (png_ptr->current_buffer_size)
+ {
+ png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
+ png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
+ png_ptr->save_buffer_size += png_ptr->current_buffer_size;
+ png_ptr->current_buffer_size = 0;
+ }
+ png_ptr->save_buffer_ptr = png_ptr->save_buffer;
+ png_ptr->buffer_size = 0;
+}
+
+void /* PRIVATE */
+png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
+ png_size_t buffer_length)
+{
+ png_ptr->current_buffer = buffer;
+ png_ptr->current_buffer_size = buffer_length;
+ png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
+ png_ptr->current_buffer_ptr = png_ptr->current_buffer;
+}
+
+void /* PRIVATE */
+png_push_read_IDAT(png_structp png_ptr)
+{
+ PNG_IDAT;
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
+ {
+ png_byte chunk_length[4];
+
+ if (png_ptr->buffer_size < 8)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_fill_buffer(png_ptr, chunk_length, 4);
+ png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
+ png_reset_crc(png_ptr);
+ png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+
+ if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ {
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+ png_error(png_ptr, "Not enough compressed data");
+ return;
+ }
+
+ png_ptr->idat_size = png_ptr->push_length;
+ }
+ if (png_ptr->idat_size && png_ptr->save_buffer_size)
+ {
+ png_size_t save_size;
+
+ if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
+ {
+ save_size = (png_size_t)png_ptr->idat_size;
+
+ /* Check for overflow */
+ if ((png_uint_32)save_size != png_ptr->idat_size)
+ png_error(png_ptr, "save_size overflowed in pngpread");
+ }
+ else
+ save_size = png_ptr->save_buffer_size;
+
+ png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
+
+ png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
+
+ png_ptr->idat_size -= save_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->save_buffer_size -= save_size;
+ png_ptr->save_buffer_ptr += save_size;
+ }
+ if (png_ptr->idat_size && png_ptr->current_buffer_size)
+ {
+ png_size_t save_size;
+
+ if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
+ {
+ save_size = (png_size_t)png_ptr->idat_size;
+
+ /* Check for overflow */
+ if ((png_uint_32)save_size != png_ptr->idat_size)
+ png_error(png_ptr, "save_size overflowed in pngpread");
+ }
+ else
+ save_size = png_ptr->current_buffer_size;
+
+ png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
+
+ png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
+
+ png_ptr->idat_size -= save_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->current_buffer_size -= save_size;
+ png_ptr->current_buffer_ptr += save_size;
+ }
+ if (!png_ptr->idat_size)
+ {
+ if (png_ptr->buffer_size < 4)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_crc_finish(png_ptr, 0);
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ }
+}
+
+void /* PRIVATE */
+png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
+ png_size_t buffer_length)
+{
+ /* The caller checks for a non-zero buffer length. */
+ if (!(buffer_length > 0) || buffer == NULL)
+ png_error(png_ptr, "No IDAT data (internal error)");
+
+ /* This routine must process all the data it has been given
+ * before returning, calling the row callback as required to
+ * handle the uncompressed results.
+ */
+ png_ptr->zstream.next_in = buffer;
+ png_ptr->zstream.avail_in = (uInt)buffer_length;
+
+ /* Keep going until the decompressed data is all processed
+ * or the stream marked as finished.
+ */
+ while (png_ptr->zstream.avail_in > 0 &&
+ !(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+ {
+ int ret;
+
+ /* We have data for zlib, but we must check that zlib
+ * has somewhere to put the results. It doesn't matter
+ * if we don't expect any results -- it may be the input
+ * data is just the LZ end code.
+ */
+ if (!(png_ptr->zstream.avail_out > 0))
+ {
+ png_ptr->zstream.avail_out =
+ (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
+ png_ptr->iwidth) + 1;
+ png_ptr->zstream.next_out = png_ptr->row_buf;
+ }
+
+ /* Using Z_SYNC_FLUSH here means that an unterminated
+ * LZ stream can still be handled (a stream with a missing
+ * end code), otherwise (Z_NO_FLUSH) a future zlib
+ * implementation might defer output and, therefore,
+ * change the current behavior. (See comments in inflate.c
+ * for why this doesn't happen at present with zlib 1.2.5.)
+ */
+ ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH);
+
+ /* Check for any failure before proceeding. */
+ if (ret != Z_OK && ret != Z_STREAM_END)
+ {
+ /* Terminate the decompression. */
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+
+ /* This may be a truncated stream (missing or
+ * damaged end code). Treat that as a warning.
+ */
+ if (png_ptr->row_number >= png_ptr->num_rows ||
+ png_ptr->pass > 6)
+ png_warning(png_ptr, "Truncated compressed data in IDAT");
+ else
+ png_error(png_ptr, "Decompression error in IDAT");
+
+ /* Skip the check on unprocessed input */
+ return;
+ }
+
+ /* Did inflate output any data? */
+ if (png_ptr->zstream.next_out != png_ptr->row_buf)
+ {
+ /* Is this unexpected data after the last row?
+ * If it is, artificially terminate the LZ output
+ * here.
+ */
+ if (png_ptr->row_number >= png_ptr->num_rows ||
+ png_ptr->pass > 6)
+ {
+ /* Extra data. */
+ png_warning(png_ptr, "Extra compressed data in IDAT");
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ /* Do no more processing; skip the unprocessed
+ * input check below.
+ */
+ return;
+ }
+
+ /* Do we have a complete row? */
+ if (png_ptr->zstream.avail_out == 0)
+ png_push_process_row(png_ptr);
+ }
+
+ /* And check for the end of the stream. */
+ if (ret == Z_STREAM_END)
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ }
+
+ /* All the data should have been processed, if anything
+ * is left at this point we have bytes of IDAT data
+ * after the zlib end code.
+ */
+ if (png_ptr->zstream.avail_in > 0)
+ png_warning(png_ptr, "Extra compression data");
+}
+
+void /* PRIVATE */
+png_push_process_row(png_structp png_ptr)
+{
+ png_ptr->row_info.color_type = png_ptr->color_type;
+ png_ptr->row_info.width = png_ptr->iwidth;
+ png_ptr->row_info.channels = png_ptr->channels;
+ png_ptr->row_info.bit_depth = png_ptr->bit_depth;
+ png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
+
+ png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
+ png_ptr->row_info.width);
+
+ png_read_filter_row(png_ptr, &(png_ptr->row_info),
+ png_ptr->row_buf + 1, png_ptr->prev_row + 1,
+ (int)(png_ptr->row_buf[0]));
+
+ png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);
+
+ if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
+ png_do_read_transformations(png_ptr);
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Blow up interlaced rows to full size */
+ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+ {
+ if (png_ptr->pass < 6)
+/* old interface (pre-1.0.9):
+ png_do_read_interlace(&(png_ptr->row_info),
+ png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
+ */
+ png_do_read_interlace(png_ptr);
+
+ switch (png_ptr->pass)
+ {
+ case 0:
+ {
+ int i;
+ for (i = 0; i < 8 && png_ptr->pass == 0; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
+ }
+
+ if (png_ptr->pass == 2) /* Pass 1 might be empty */
+ {
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ if (png_ptr->pass == 4 && png_ptr->height <= 4)
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ if (png_ptr->pass == 6 && png_ptr->height <= 4)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ break;
+ }
+
+ case 1:
+ {
+ int i;
+ for (i = 0; i < 8 && png_ptr->pass == 1; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 2) /* Skip top 4 generated rows */
+ {
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ break;
+ }
+
+ case 2:
+ {
+ int i;
+
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 4) /* Pass 3 might be empty */
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ break;
+ }
+
+ case 3:
+ {
+ int i;
+
+ for (i = 0; i < 4 && png_ptr->pass == 3; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 4) /* Skip top two generated rows */
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ break;
+ }
+
+ case 4:
+ {
+ int i;
+
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 6) /* Pass 5 might be empty */
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ break;
+ }
+
+ case 5:
+ {
+ int i;
+
+ for (i = 0; i < 2 && png_ptr->pass == 5; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 6) /* Skip top generated row */
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ break;
+ }
+ case 6:
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+
+ if (png_ptr->pass != 6)
+ break;
+
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+ }
+ else
+#endif
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+}
+
+void /* PRIVATE */
+png_read_push_finish_row(png_structp png_ptr)
+{
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+
+ /* Height of interlace block. This is not currently used - if you need
+ * it, uncomment it here and in png.h
+ PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+ */
+
+ png_ptr->row_number++;
+ if (png_ptr->row_number < png_ptr->num_rows)
+ return;
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if (png_ptr->interlaced)
+ {
+ png_ptr->row_number = 0;
+ png_memset(png_ptr->prev_row, 0,
+ png_ptr->rowbytes + 1);
+ do
+ {
+ png_ptr->pass++;
+ if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
+ (png_ptr->pass == 3 && png_ptr->width < 3) ||
+ (png_ptr->pass == 5 && png_ptr->width < 2))
+ png_ptr->pass++;
+
+ if (png_ptr->pass > 7)
+ png_ptr->pass--;
+
+ if (png_ptr->pass >= 7)
+ break;
+
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+
+ if (png_ptr->transformations & PNG_INTERLACE)
+ break;
+
+ png_ptr->num_rows = (png_ptr->height +
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
+
+ } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
+ }
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+}
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+void /* PRIVATE */
+png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
+ length)
+{
+ if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
+ {
+ png_error(png_ptr, "Out of place tEXt");
+ info_ptr = info_ptr; /* To quiet some compiler warnings */
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ png_ptr->skip_length = 0; /* This may not be necessary */
+
+ if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
+ {
+ png_warning(png_ptr, "tEXt chunk too large to fit in memory");
+ png_ptr->skip_length = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_ptr->current_text = (png_charp)png_malloc(png_ptr,
+ (png_size_t)(length + 1));
+ png_ptr->current_text[length] = '\0';
+ png_ptr->current_text_ptr = png_ptr->current_text;
+ png_ptr->current_text_size = (png_size_t)length;
+ png_ptr->current_text_left = (png_size_t)length;
+ png_ptr->process_mode = PNG_READ_tEXt_MODE;
+}
+
+void /* PRIVATE */
+png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr->buffer_size && png_ptr->current_text_left)
+ {
+ png_size_t text_size;
+
+ if (png_ptr->buffer_size < png_ptr->current_text_left)
+ text_size = png_ptr->buffer_size;
+
+ else
+ text_size = png_ptr->current_text_left;
+
+ png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
+ png_ptr->current_text_left -= text_size;
+ png_ptr->current_text_ptr += text_size;
+ }
+ if (!(png_ptr->current_text_left))
+ {
+ png_textp text_ptr;
+ png_charp text;
+ png_charp key;
+ int ret;
+
+ if (png_ptr->buffer_size < 4)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_crc_finish(png_ptr);
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (png_ptr->skip_length)
+ return;
+#endif
+
+ key = png_ptr->current_text;
+
+ for (text = key; *text; text++)
+ /* Empty loop */ ;
+
+ if (text < key + png_ptr->current_text_size)
+ text++;
+
+ text_ptr = (png_textp)png_malloc(png_ptr,
+ png_sizeof(png_text));
+ text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
+ text_ptr->key = key;
+#ifdef PNG_iTXt_SUPPORTED
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+#endif
+ text_ptr->text = text;
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, key);
+ png_free(png_ptr, text_ptr);
+ png_ptr->current_text = NULL;
+
+ if (ret)
+ png_warning(png_ptr, "Insufficient memory to store text chunk");
+ }
+}
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+void /* PRIVATE */
+png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
+ length)
+{
+ if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
+ {
+ png_error(png_ptr, "Out of place zTXt");
+ info_ptr = info_ptr; /* To quiet some compiler warnings */
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ /* We can't handle zTXt chunks > 64K, since we don't have enough space
+ * to be able to store the uncompressed data. Actually, the threshold
+ * is probably around 32K, but it isn't as definite as 64K is.
+ */
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "zTXt chunk too large to fit in memory");
+ png_push_crc_skip(png_ptr, length);
+ return;
+ }
+#endif
+
+ png_ptr->current_text = (png_charp)png_malloc(png_ptr,
+ (png_size_t)(length + 1));
+ png_ptr->current_text[length] = '\0';
+ png_ptr->current_text_ptr = png_ptr->current_text;
+ png_ptr->current_text_size = (png_size_t)length;
+ png_ptr->current_text_left = (png_size_t)length;
+ png_ptr->process_mode = PNG_READ_zTXt_MODE;
+}
+
+void /* PRIVATE */
+png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr->buffer_size && png_ptr->current_text_left)
+ {
+ png_size_t text_size;
+
+ if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
+ text_size = png_ptr->buffer_size;
+
+ else
+ text_size = png_ptr->current_text_left;
+
+ png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
+ png_ptr->current_text_left -= text_size;
+ png_ptr->current_text_ptr += text_size;
+ }
+ if (!(png_ptr->current_text_left))
+ {
+ png_textp text_ptr;
+ png_charp text;
+ png_charp key;
+ int ret;
+ png_size_t text_size, key_size;
+
+ if (png_ptr->buffer_size < 4)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_crc_finish(png_ptr);
+
+ key = png_ptr->current_text;
+
+ for (text = key; *text; text++)
+ /* Empty loop */ ;
+
+ /* zTXt can't have zero text */
+ if (text >= key + png_ptr->current_text_size)
+ {
+ png_ptr->current_text = NULL;
+ png_free(png_ptr, key);
+ return;
+ }
+
+ text++;
+
+ if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */
+ {
+ png_ptr->current_text = NULL;
+ png_free(png_ptr, key);
+ return;
+ }
+
+ text++;
+
+ png_ptr->zstream.next_in = (png_bytep )text;
+ png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
+ (text - key));
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+
+ key_size = text - key;
+ text_size = 0;
+ text = NULL;
+ ret = Z_STREAM_END;
+
+ while (png_ptr->zstream.avail_in)
+ {
+ ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+ if (ret != Z_OK && ret != Z_STREAM_END)
+ {
+ inflateReset(&png_ptr->zstream);
+ png_ptr->zstream.avail_in = 0;
+ png_ptr->current_text = NULL;
+ png_free(png_ptr, key);
+ png_free(png_ptr, text);
+ return;
+ }
+ if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
+ {
+ if (text == NULL)
+ {
+ text = (png_charp)png_malloc(png_ptr,
+ (png_ptr->zbuf_size
+ - png_ptr->zstream.avail_out + key_size + 1));
+
+ png_memcpy(text + key_size, png_ptr->zbuf,
+ png_ptr->zbuf_size - png_ptr->zstream.avail_out);
+
+ png_memcpy(text, key, key_size);
+
+ text_size = key_size + png_ptr->zbuf_size -
+ png_ptr->zstream.avail_out;
+
+ *(text + text_size) = '\0';
+ }
+ else
+ {
+ png_charp tmp;
+
+ tmp = text;
+ text = (png_charp)png_malloc(png_ptr, text_size +
+ (png_ptr->zbuf_size
+ - png_ptr->zstream.avail_out + 1));
+
+ png_memcpy(text, tmp, text_size);
+ png_free(png_ptr, tmp);
+
+ png_memcpy(text + text_size, png_ptr->zbuf,
+ png_ptr->zbuf_size - png_ptr->zstream.avail_out);
+
+ text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+ *(text + text_size) = '\0';
+ }
+ if (ret != Z_STREAM_END)
+ {
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ }
+ }
+ else
+ {
+ break;
+ }
+
+ if (ret == Z_STREAM_END)
+ break;
+ }
+
+ inflateReset(&png_ptr->zstream);
+ png_ptr->zstream.avail_in = 0;
+
+ if (ret != Z_STREAM_END)
+ {
+ png_ptr->current_text = NULL;
+ png_free(png_ptr, key);
+ png_free(png_ptr, text);
+ return;
+ }
+
+ png_ptr->current_text = NULL;
+ png_free(png_ptr, key);
+ key = text;
+ text += key_size;
+
+ text_ptr = (png_textp)png_malloc(png_ptr,
+ png_sizeof(png_text));
+ text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
+ text_ptr->key = key;
+#ifdef PNG_iTXt_SUPPORTED
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+#endif
+ text_ptr->text = text;
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, key);
+ png_free(png_ptr, text_ptr);
+
+ if (ret)
+ png_warning(png_ptr, "Insufficient memory to store text chunk");
+ }
+}
+#endif
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+void /* PRIVATE */
+png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
+ length)
+{
+ if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
+ {
+ png_error(png_ptr, "Out of place iTXt");
+ info_ptr = info_ptr; /* To quiet some compiler warnings */
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ png_ptr->skip_length = 0; /* This may not be necessary */
+
+ if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
+ {
+ png_warning(png_ptr, "iTXt chunk too large to fit in memory");
+ png_ptr->skip_length = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_ptr->current_text = (png_charp)png_malloc(png_ptr,
+ (png_size_t)(length + 1));
+ png_ptr->current_text[length] = '\0';
+ png_ptr->current_text_ptr = png_ptr->current_text;
+ png_ptr->current_text_size = (png_size_t)length;
+ png_ptr->current_text_left = (png_size_t)length;
+ png_ptr->process_mode = PNG_READ_iTXt_MODE;
+}
+
+void /* PRIVATE */
+png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
+{
+
+ if (png_ptr->buffer_size && png_ptr->current_text_left)
+ {
+ png_size_t text_size;
+
+ if (png_ptr->buffer_size < png_ptr->current_text_left)
+ text_size = png_ptr->buffer_size;
+
+ else
+ text_size = png_ptr->current_text_left;
+
+ png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
+ png_ptr->current_text_left -= text_size;
+ png_ptr->current_text_ptr += text_size;
+ }
+ if (!(png_ptr->current_text_left))
+ {
+ png_textp text_ptr;
+ png_charp key;
+ int comp_flag;
+ png_charp lang;
+ png_charp lang_key;
+ png_charp text;
+ int ret;
+
+ if (png_ptr->buffer_size < 4)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_crc_finish(png_ptr);
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (png_ptr->skip_length)
+ return;
+#endif
+
+ key = png_ptr->current_text;
+
+ for (lang = key; *lang; lang++)
+ /* Empty loop */ ;
+
+ if (lang < key + png_ptr->current_text_size - 3)
+ lang++;
+
+ comp_flag = *lang++;
+ lang++; /* Skip comp_type, always zero */
+
+ for (lang_key = lang; *lang_key; lang_key++)
+ /* Empty loop */ ;
+
+ lang_key++; /* Skip NUL separator */
+
+ text=lang_key;
+
+ if (lang_key < key + png_ptr->current_text_size - 1)
+ {
+ for (; *text; text++)
+ /* Empty loop */ ;
+ }
+
+ if (text < key + png_ptr->current_text_size)
+ text++;
+
+ text_ptr = (png_textp)png_malloc(png_ptr,
+ png_sizeof(png_text));
+
+ text_ptr->compression = comp_flag + 2;
+ text_ptr->key = key;
+ text_ptr->lang = lang;
+ text_ptr->lang_key = lang_key;
+ text_ptr->text = text;
+ text_ptr->text_length = 0;
+ text_ptr->itxt_length = png_strlen(text);
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_ptr->current_text = NULL;
+
+ png_free(png_ptr, text_ptr);
+ if (ret)
+ png_warning(png_ptr, "Insufficient memory to store iTXt chunk");
+ }
+}
+#endif
+
+/* This function is called when we haven't found a handler for this
+ * chunk. If there isn't a problem with the chunk itself (ie a bad chunk
+ * name or a critical chunk), the chunk is (currently) silently ignored.
+ */
+void /* PRIVATE */
+png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
+ length)
+{
+ png_uint_32 skip = 0;
+
+ if (!(png_ptr->chunk_name[0] & 0x20))
+ {
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+ if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ && png_ptr->read_user_chunk_fn == NULL
+#endif
+ )
+#endif
+ png_chunk_error(png_ptr, "unknown critical chunk");
+
+ info_ptr = info_ptr; /* To quiet some compiler warnings */
+ }
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+ if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
+ {
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "unknown chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+ png_memcpy((png_charp)png_ptr->unknown_chunk.name,
+ (png_charp)png_ptr->chunk_name,
+ png_sizeof(png_ptr->unknown_chunk.name));
+ png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1]
+ = '\0';
+
+ png_ptr->unknown_chunk.size = (png_size_t)length;
+
+ if (length == 0)
+ png_ptr->unknown_chunk.data = NULL;
+
+ else
+ {
+ png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
+ (png_size_t)length);
+ png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
+ }
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ if (png_ptr->read_user_chunk_fn != NULL)
+ {
+ /* Callback to user unknown chunk handler */
+ int ret;
+ ret = (*(png_ptr->read_user_chunk_fn))
+ (png_ptr, &png_ptr->unknown_chunk);
+
+ if (ret < 0)
+ png_chunk_error(png_ptr, "error in user chunk");
+
+ if (ret == 0)
+ {
+ if (!(png_ptr->chunk_name[0] & 0x20))
+ if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS)
+ png_chunk_error(png_ptr, "unknown critical chunk");
+ png_set_unknown_chunks(png_ptr, info_ptr,
+ &png_ptr->unknown_chunk, 1);
+ }
+ }
+
+ else
+#endif
+ png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+ }
+
+ else
+#endif
+ skip=length;
+ png_push_crc_skip(png_ptr, skip);
+}
+
+void /* PRIVATE */
+png_push_have_info(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr->info_fn != NULL)
+ (*(png_ptr->info_fn))(png_ptr, info_ptr);
+}
+
+void /* PRIVATE */
+png_push_have_end(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr->end_fn != NULL)
+ (*(png_ptr->end_fn))(png_ptr, info_ptr);
+}
+
+void /* PRIVATE */
+png_push_have_row(png_structp png_ptr, png_bytep row)
+{
+ if (png_ptr->row_fn != NULL)
+ (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
+ (int)png_ptr->pass);
+}
+
+void PNGAPI
+png_progressive_combine_row (png_structp png_ptr,
+ png_bytep old_row, png_bytep new_row)
+{
+ PNG_CONST int FARDATA png_pass_dsp_mask[7] =
+ {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
+
+ if (png_ptr == NULL)
+ return;
+
+ if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
+ png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
+}
+
+void PNGAPI
+png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
+ png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
+ png_progressive_end_ptr end_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->info_fn = info_fn;
+ png_ptr->row_fn = row_fn;
+ png_ptr->end_fn = end_fn;
+
+ png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
+}
+
+png_voidp PNGAPI
+png_get_progressive_ptr(png_structp png_ptr)
+{
+ if (png_ptr == NULL)
+ return (NULL);
+
+ return png_ptr->io_ptr;
+}
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
--- /dev/null
+
+/* pngpriv.h - private declarations for use inside libpng
+ *
+ * libpng version 1.4.4 - September 23, 2010
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* The symbols declared in this file (including the functions declared
+ * as PNG_EXTERN) are PRIVATE. They are not part of the libpng public
+ * interface, and are not recommended for use by regular applications.
+ * Some of them may become public in the future; others may stay private,
+ * change in an incompatible way, or even disappear.
+ * Although the libpng users are not forbidden to include this header,
+ * they should be well aware of the issues that may arise from doing so.
+ */
+
+#ifndef PNGPRIV_H
+#define PNGPRIV_H
+
+#ifndef PNG_VERSION_INFO_ONLY
+
+#include <stdlib.h>
+
+#ifndef PNG_EXTERN
+/* The functions exported by PNG_EXTERN are internal functions, which
+ * aren't usually used outside the library (as far as I know), so it is
+ * debatable if they should be exported at all. In the future, when it
+ * is possible to have run-time registry of chunk-handling functions,
+ * some of these will be made available again.
+# define PNG_EXTERN extern
+ */
+# define PNG_EXTERN
+#endif
+
+/* Other defines specific to compilers can go here. Try to keep
+ * them inside an appropriate ifdef/endif pair for portability.
+ */
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+# ifdef MACOS
+ /* We need to check that <math.h> hasn't already been included earlier
+ * as it seems it doesn't agree with <fp.h>, yet we should really use
+ * <fp.h> if possible.
+ */
+# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
+# include <fp.h>
+# endif
+# else
+# include <math.h>
+# endif
+# if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
+ /* Amiga SAS/C: We must include builtin FPU functions when compiling using
+ * MATH=68881
+ */
+# include <m68881.h>
+# endif
+#endif
+
+/* Codewarrior on NT has linking problems without this. */
+#if (defined(__MWERKS__) && defined(WIN32)) || defined(__STDC__)
+# define PNG_ALWAYS_EXTERN
+#endif
+
+/* This provides the non-ANSI (far) memory allocation routines. */
+#if defined(__TURBOC__) && defined(__MSDOS__)
+# include <mem.h>
+# include <alloc.h>
+#endif
+
+#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
+ defined(_WIN32) || defined(__WIN32__)
+# include <windows.h> /* defines _WINDOWS_ macro */
+#endif
+
+/* Various modes of operation. Note that after an init, mode is set to
+ * zero automatically when the structure is created.
+ */
+#define PNG_HAVE_IHDR 0x01
+#define PNG_HAVE_PLTE 0x02
+#define PNG_HAVE_IDAT 0x04
+#define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
+#define PNG_HAVE_IEND 0x10
+#define PNG_HAVE_gAMA 0x20
+#define PNG_HAVE_cHRM 0x40
+#define PNG_HAVE_sRGB 0x80
+#define PNG_HAVE_CHUNK_HEADER 0x100
+#define PNG_WROTE_tIME 0x200
+#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
+#define PNG_BACKGROUND_IS_GRAY 0x800
+#define PNG_HAVE_PNG_SIGNATURE 0x1000
+#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
+
+/* Flags for the transformations the PNG library does on the image data */
+#define PNG_BGR 0x0001
+#define PNG_INTERLACE 0x0002
+#define PNG_PACK 0x0004
+#define PNG_SHIFT 0x0008
+#define PNG_SWAP_BYTES 0x0010
+#define PNG_INVERT_MONO 0x0020
+#define PNG_QUANTIZE 0x0040 /* formerly PNG_DITHER */
+#define PNG_BACKGROUND 0x0080
+#define PNG_BACKGROUND_EXPAND 0x0100
+ /* 0x0200 unused */
+#define PNG_16_TO_8 0x0400
+#define PNG_RGBA 0x0800
+#define PNG_EXPAND 0x1000
+#define PNG_GAMMA 0x2000
+#define PNG_GRAY_TO_RGB 0x4000
+#define PNG_FILLER 0x8000L
+#define PNG_PACKSWAP 0x10000L
+#define PNG_SWAP_ALPHA 0x20000L
+#define PNG_STRIP_ALPHA 0x40000L
+#define PNG_INVERT_ALPHA 0x80000L
+#define PNG_USER_TRANSFORM 0x100000L
+#define PNG_RGB_TO_GRAY_ERR 0x200000L
+#define PNG_RGB_TO_GRAY_WARN 0x400000L
+#define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */
+ /* 0x800000L Unused */
+#define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */
+#define PNG_EXPAND_tRNS 0x2000000L /* Added to libpng-1.2.9 */
+ /* 0x4000000L unused */
+ /* 0x8000000L unused */
+ /* 0x10000000L unused */
+ /* 0x20000000L unused */
+ /* 0x40000000L unused */
+
+/* Flags for png_create_struct */
+#define PNG_STRUCT_PNG 0x0001
+#define PNG_STRUCT_INFO 0x0002
+
+/* Scaling factor for filter heuristic weighting calculations */
+#define PNG_WEIGHT_SHIFT 8
+#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
+#define PNG_COST_SHIFT 3
+#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
+
+/* Flags for the png_ptr->flags rather than declaring a byte for each one */
+#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
+#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
+#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
+#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
+#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
+#define PNG_FLAG_ZLIB_FINISHED 0x0020
+#define PNG_FLAG_ROW_INIT 0x0040
+#define PNG_FLAG_FILLER_AFTER 0x0080
+#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
+#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
+#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
+#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
+ /* 0x1000 unused */
+ /* 0x2000 unused */
+ /* 0x4000 unused */
+#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
+#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
+#define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
+#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L
+#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L
+#define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L
+#define PNG_FLAG_ADD_ALPHA 0x200000L /* Added to libpng-1.2.8 */
+#define PNG_FLAG_STRIP_ALPHA 0x400000L /* Added to libpng-1.2.8 */
+#define PNG_FLAG_BENIGN_ERRORS_WARN 0x800000L /* Added to libpng-1.4.0 */
+ /* 0x1000000L unused */
+ /* 0x2000000L unused */
+ /* 0x4000000L unused */
+ /* 0x8000000L unused */
+ /* 0x10000000L unused */
+ /* 0x20000000L unused */
+ /* 0x40000000L unused */
+
+#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
+ PNG_FLAG_CRC_ANCILLARY_NOWARN)
+
+#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
+ PNG_FLAG_CRC_CRITICAL_IGNORE)
+
+#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
+ PNG_FLAG_CRC_CRITICAL_MASK)
+
+/* Save typing and make code easier to understand */
+
+#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
+ abs((int)((c1).green) - (int)((c2).green)) + \
+ abs((int)((c1).blue) - (int)((c2).blue)))
+
+/* Added to libpng-1.2.6 JB */
+#define PNG_ROWBYTES(pixel_bits, width) \
+ ((pixel_bits) >= 8 ? \
+ ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
+ (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
+
+/* PNG_OUT_OF_RANGE returns true if value is outside the range
+ * ideal-delta..ideal+delta. Each argument is evaluated twice.
+ * "ideal" and "delta" should be constants, normally simple
+ * integers, "value" a variable. Added to libpng-1.2.6 JB
+ */
+#define PNG_OUT_OF_RANGE(value, ideal, delta) \
+ ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
+
+/* Constant strings for known chunk types. If you need to add a chunk,
+ * define the name here, and add an invocation of the macro wherever it's
+ * needed.
+ */
+#define PNG_IHDR PNG_CONST png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
+#define PNG_IDAT PNG_CONST png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
+#define PNG_IEND PNG_CONST png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
+#define PNG_PLTE PNG_CONST png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
+#define PNG_bKGD PNG_CONST png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
+#define PNG_cHRM PNG_CONST png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
+#define PNG_gAMA PNG_CONST png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
+#define PNG_hIST PNG_CONST png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
+#define PNG_iCCP PNG_CONST png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
+#define PNG_iTXt PNG_CONST png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
+#define PNG_oFFs PNG_CONST png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
+#define PNG_pCAL PNG_CONST png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
+#define PNG_sCAL PNG_CONST png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
+#define PNG_pHYs PNG_CONST png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
+#define PNG_sBIT PNG_CONST png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
+#define PNG_sPLT PNG_CONST png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
+#define PNG_sRGB PNG_CONST png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
+#define PNG_sTER PNG_CONST png_byte png_sTER[5] = {115, 84, 69, 82, '\0'}
+#define PNG_tEXt PNG_CONST png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
+#define PNG_tIME PNG_CONST png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
+#define PNG_tRNS PNG_CONST png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
+#define PNG_zTXt PNG_CONST png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
+
+
+/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/* These functions are used internally in the code. They generally
+ * shouldn't be used unless you are writing code to add or replace some
+ * functionality in libpng. More information about most functions can
+ * be found in the files where the functions are located.
+ */
+
+/* Allocate memory for an internal libpng struct */
+PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
+
+/* Free memory from internal libpng struct */
+PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
+
+PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
+ malloc_fn, png_voidp mem_ptr));
+PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
+ png_free_ptr free_fn, png_voidp mem_ptr));
+
+/* Free any memory that info_ptr points to and reset struct. */
+PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+
+/* Function to allocate memory for zlib. PNGAPI is disallowed. */
+PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
+
+/* Function to free memory for zlib. PNGAPI is disallowed. */
+PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
+
+/* Next four functions are used internally as callbacks. PNGAPI is required
+ * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3. */
+
+PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
+ png_bytep data, png_size_t length));
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
+ png_bytep buffer, png_size_t length));
+#endif
+
+PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
+ png_bytep data, png_size_t length));
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+#ifdef PNG_STDIO_SUPPORTED
+PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr));
+#endif
+#endif
+
+/* Reset the CRC variable */
+PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
+
+/* Write the "data" buffer to whatever output you are using */
+PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
+ png_size_t length));
+
+/* Read the chunk header (length + type name) */
+PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
+
+/* Read data from whatever input you are using into the "data" buffer */
+PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
+ png_size_t length));
+
+/* Read bytes into buf, and update png_ptr->crc */
+PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
+ png_size_t length));
+
+/* Decompress data in a chunk that uses compression */
+#if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
+ defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
+PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
+ int comp_type, png_size_t chunklength, png_size_t prefix_length,
+ png_size_t *data_length));
+#endif
+
+/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
+PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
+
+/* Read the CRC from the file and compare it to the libpng calculated CRC */
+PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
+
+/* Calculate the CRC over a section of data. Note that we are only
+ * passing a maximum of 64K on systems that have this as a memory limit,
+ * since this is the maximum buffer size we can specify.
+ */
+PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
+ png_size_t length));
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
+#endif
+
+/* Write various chunks */
+
+/* Write the IHDR chunk, and update the png_struct with the necessary
+ * information.
+ */
+PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
+ png_uint_32 height,
+ int bit_depth, int color_type, int compression_method, int filter_method,
+ int interlace_method));
+
+PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
+ png_uint_32 num_pal));
+
+PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
+ png_size_t length));
+
+PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
+
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr,
+ png_fixed_point file_gamma));
+#endif
+#endif
+
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
+ int color_type));
+#endif
+
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
+ double white_x, double white_y,
+ double red_x, double red_y, double green_x, double green_y,
+ double blue_x, double blue_y));
+#endif
+PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
+ png_fixed_point int_white_x, png_fixed_point int_white_y,
+ png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
+ int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
+ png_fixed_point int_blue_y));
+#endif
+
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
+ int intent));
+#endif
+
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
+ png_charp name, int compression_type,
+ png_charp profile, int proflen));
+ /* Note to maintainer: profile should be png_bytep */
+#endif
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
+ png_sPLT_tp palette));
+#endif
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
+ png_color_16p values, int number, int color_type));
+#endif
+
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
+ png_color_16p values, int color_type));
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
+ int num_hist));
+#endif
+
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
+ defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
+ png_charp key, png_charpp new_key));
+#endif
+
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
+ png_charp text, png_size_t text_len));
+#endif
+
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
+ png_charp text, png_size_t text_len, int compression));
+#endif
+
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
+ int compression, png_charp key, png_charp lang, png_charp lang_key,
+ png_charp text));
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
+PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_textp text_ptr, int num_text));
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
+ png_int_32 x_offset, png_int_32 y_offset, int unit_type));
+#endif
+
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
+ png_int_32 X0, png_int_32 X1, int type, int nparams,
+ png_charp units, png_charpp params));
+#endif
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
+ png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
+ int unit_type));
+#endif
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
+ png_timep mod_time));
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
+PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
+ int unit, double width, double height));
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
+ int unit, png_charp width, png_charp height));
+#endif
+#endif
+#endif
+
+/* Called when finished processing a row of data */
+PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
+
+/* Internal use only. Called before first row of data */
+PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr,
+ png_byte bit_depth));
+#endif
+
+/* Combine a row of data, dealing with alpha, etc. if requested */
+PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
+ int mask));
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+/* Expand an interlaced row */
+/* OLD pre-1.0.9 interface:
+PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
+ png_bytep row, int pass, png_uint_32 transformations));
+ */
+PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
+#endif
+
+/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+/* Grab pixels out of a row for an interlaced pass */
+PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
+ png_bytep row, int pass));
+#endif
+
+/* Unfilter a row */
+PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
+ png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
+
+/* Choose the best filter to use and filter the row data */
+PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
+ png_row_infop row_info));
+
+/* Write out the filtered row. */
+PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
+ png_bytep filtered_row));
+/* Finish a row while reading, dealing with interlacing passes, etc. */
+PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
+
+/* Initialize the row buffers, etc. */
+PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
+/* Optional call to update the users info structure */
+PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+
+/* These are the functions that do the transformations */
+#ifdef PNG_READ_FILLER_SUPPORTED
+PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
+ png_bytep row, png_uint_32 filler, png_uint_32 flags));
+#endif
+
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+ defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
+ png_bytep row, png_uint_32 flags));
+#endif
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
+ defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
+ row_info, png_bytep row));
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+#ifdef PNG_READ_PACK_SUPPORTED
+PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
+ png_color_8p sig_bits));
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+PNG_EXTERN void png_do_quantize PNGARG((png_row_infop row_info,
+ png_bytep row, png_bytep palette_lookup, png_bytep quantize_lookup));
+
+# ifdef PNG_CORRECT_PALETTE_SUPPORTED
+PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
+ png_colorp palette, int num_palette));
+# endif
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
+ png_bytep row, png_uint_32 bit_depth));
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
+ png_color_8p bit_depth));
+#endif
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+#ifdef PNG_READ_GAMMA_SUPPORTED
+PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
+ png_color_16p trans_color, png_color_16p background,
+ png_color_16p background_1,
+ png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
+ png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
+ png_uint_16pp gamma_16_to_1, int gamma_shift));
+#else
+PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
+ png_color_16p trans_color, png_color_16p background));
+#endif
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
+ png_bytep gamma_table, png_uint_16pp gamma_16_table,
+ int gamma_shift));
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
+ png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
+PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
+ png_bytep row, png_color_16p trans_value));
+#endif
+
+/* The following decodes the appropriate chunks, and does error correction,
+ * then calls the appropriate callback for the chunk if it is valid.
+ */
+
+/* Decode the IHDR chunk */
+PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+PNG_EXTERN void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif /* PNG_READ_iCCP_SUPPORTED */
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_oFFs_SUPPORTED
+PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_pHYs_SUPPORTED
+PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+PNG_EXTERN void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif /* PNG_READ_sPLT_SUPPORTED */
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 length));
+
+PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
+ png_bytep chunk_name));
+
+/* Handle the transformations for reading and writing */
+PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
+
+PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
+ png_uint_32 length));
+PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
+ png_bytep buffer, png_size_t buffer_length));
+PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
+ png_bytep buffer, png_size_t buffer_length));
+PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
+PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
+#ifdef PNG_READ_tEXt_SUPPORTED
+PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+#endif
+
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
+ png_bytep row));
+PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+/* Added at libpng version 1.4.0 */
+#ifdef PNG_cHRM_SUPPORTED
+PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
+ png_fixed_point int_white_x, png_fixed_point int_white_y,
+ png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
+ int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
+ png_fixed_point int_blue_y));
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+#ifdef PNG_CHECK_cHRM_SUPPORTED
+/* Added at libpng version 1.2.34 and 1.4.0 */
+PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
+ unsigned long *hi_product, unsigned long *lo_product));
+#endif
+#endif
+
+/* Added at libpng version 1.4.0 */
+PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_type, int compression_type,
+ int filter_type));
+
+/* Free all memory used by the read (old method - NOT DLL EXPORTED) */
+PNG_EXTERN void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_infop end_info_ptr));
+
+/* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
+PNG_EXTERN void png_write_destroy PNGARG((png_structp png_ptr));
+
+#ifdef USE_FAR_KEYWORD /* memory model conversion function */
+PNG_EXTERN void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
+ int check));
+#endif /* USE_FAR_KEYWORD */
+
+/* Define PNG_DEBUG at compile time for debugging information. Higher
+ * numbers for PNG_DEBUG mean more debugging information. This has
+ * only been added since version 0.95 so it is not implemented throughout
+ * libpng yet, but more support will be added as needed.
+ */
+#ifdef PNG_DEBUG
+#if (PNG_DEBUG > 0)
+#if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
+#include <crtdbg.h>
+#if (PNG_DEBUG > 1)
+#ifndef _DEBUG
+# define _DEBUG
+#endif
+#ifndef png_debug
+#define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
+#endif
+#ifndef png_debug1
+#define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
+#endif
+#ifndef png_debug2
+#define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
+#endif
+#endif
+#else /* PNG_DEBUG_FILE || !_MSC_VER */
+#ifndef PNG_DEBUG_FILE
+#define PNG_DEBUG_FILE stderr
+#endif /* PNG_DEBUG_FILE */
+
+#if (PNG_DEBUG > 1)
+/* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on
+ * non-ISO compilers
+ */
+# ifdef __STDC__
+# ifndef png_debug
+# define png_debug(l,m) \
+ { \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
+ }
+# endif
+# ifndef png_debug1
+# define png_debug1(l,m,p1) \
+ { \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
+ }
+# endif
+# ifndef png_debug2
+# define png_debug2(l,m,p1,p2) \
+ { \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
+ }
+# endif
+# else /* __STDC __ */
+# ifndef png_debug
+# define png_debug(l,m) \
+ { \
+ int num_tabs=l; \
+ char format[256]; \
+ snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+ m,PNG_STRING_NEWLINE); \
+ fprintf(PNG_DEBUG_FILE,format); \
+ }
+# endif
+# ifndef png_debug1
+# define png_debug1(l,m,p1) \
+ { \
+ int num_tabs=l; \
+ char format[256]; \
+ snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+ m,PNG_STRING_NEWLINE); \
+ fprintf(PNG_DEBUG_FILE,format,p1); \
+ }
+# endif
+# ifndef png_debug2
+# define png_debug2(l,m,p1,p2) \
+ { \
+ int num_tabs=l; \
+ char format[256]; \
+ snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+ m,PNG_STRING_NEWLINE); \
+ fprintf(PNG_DEBUG_FILE,format,p1,p2); \
+ }
+# endif
+# endif /* __STDC __ */
+#endif /* (PNG_DEBUG > 1) */
+
+#endif /* _MSC_VER */
+#endif /* (PNG_DEBUG > 0) */
+#endif /* PNG_DEBUG */
+#ifndef png_debug
+#define png_debug(l, m)
+#endif
+#ifndef png_debug1
+#define png_debug1(l, m, p1)
+#endif
+#ifndef png_debug2
+#define png_debug2(l, m, p1, p2)
+#endif
+
+/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PNG_VERSION_INFO_ONLY */
+#endif /* PNGPRIV_H */
--- /dev/null
+
+/* pngread.c - read a PNG file
+ *
+ * Last changed in libpng 1.4.1 [February 25, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that an application calls directly to
+ * read a PNG file or stream.
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#ifdef PNG_READ_SUPPORTED
+#include "pngpriv.h"
+
+
+/* Create a PNG structure for reading, and allocate any memory needed. */
+png_structp PNGAPI
+png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn)
+{
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
+ warn_fn, NULL, NULL, NULL));
+}
+
+/* Alternate create PNG structure for reading, and allocate any memory
+ * needed.
+ */
+png_structp PNGAPI
+png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+#ifdef PNG_SETJMP_SUPPORTED
+ volatile
+#endif
+ png_structp png_ptr;
+ volatile int png_cleanup_needed = 0;
+
+#ifdef PNG_SETJMP_SUPPORTED
+#ifdef USE_FAR_KEYWORD
+ jmp_buf jmpbuf;
+#endif
+#endif
+
+ int i;
+
+ png_debug(1, "in png_create_read_struct");
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
+ malloc_fn, mem_ptr);
+#else
+ png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
+#endif
+ if (png_ptr == NULL)
+ return (NULL);
+
+ /* Added at libpng-1.2.6 */
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
+ png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
+# ifdef PNG_USER_CHUNK_CACHE_MAX
+ /* Added at libpng-1.2.43 and 1.4.0 */
+ png_ptr->user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX;
+# endif
+# ifdef PNG_SET_USER_CHUNK_MALLOC_MAX
+ /* Added at libpng-1.2.43 and 1.4.1 */
+ png_ptr->user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX;
+# endif
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* Applications that neglect to set up their own setjmp() and then
+ encounter a png_error() will longjmp here. Since the jmpbuf is
+ then meaningless we abort instead of returning. */
+#ifdef USE_FAR_KEYWORD
+ if (setjmp(jmpbuf))
+#else
+ if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */
+#endif
+ PNG_ABORT();
+#ifdef USE_FAR_KEYWORD
+ png_memcpy(png_jmpbuf(png_ptr), jmpbuf, png_sizeof(jmp_buf));
+#endif
+#endif /* PNG_SETJMP_SUPPORTED */
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
+#endif
+
+ png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
+
+ if (user_png_ver)
+ {
+ i = 0;
+ do
+ {
+ if (user_png_ver[i] != png_libpng_ver[i])
+ png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+ } while (png_libpng_ver[i++]);
+ }
+ else
+ png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+
+
+ if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
+ {
+ /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
+ * we must recompile any applications that use any older library version.
+ * For versions after libpng 1.0, we will be compatible, so we need
+ * only check the first digit.
+ */
+ if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
+ (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
+ (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
+ {
+#ifdef PNG_STDIO_SUPPORTED
+ char msg[80];
+ if (user_png_ver)
+ {
+ png_snprintf(msg, 80,
+ "Application was compiled with png.h from libpng-%.20s",
+ user_png_ver);
+ png_warning(png_ptr, msg);
+ }
+ png_snprintf(msg, 80,
+ "Application is running with png.c from libpng-%.20s",
+ png_libpng_ver);
+ png_warning(png_ptr, msg);
+#endif
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ png_ptr->flags = 0;
+#endif
+ png_warning(png_ptr,
+ "Incompatible libpng version in application and library");
+
+ png_cleanup_needed = 1;
+ }
+ }
+
+ if (!png_cleanup_needed)
+ {
+ /* Initialize zbuf - compression buffer */
+ png_ptr->zbuf_size = PNG_ZBUF_SIZE;
+ png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr,
+ png_ptr->zbuf_size);
+ if (png_ptr->zbuf == NULL)
+ png_cleanup_needed = 1;
+ }
+ png_ptr->zstream.zalloc = png_zalloc;
+ png_ptr->zstream.zfree = png_zfree;
+ png_ptr->zstream.opaque = (voidpf)png_ptr;
+
+ if (!png_cleanup_needed)
+ {
+ switch (inflateInit(&png_ptr->zstream))
+ {
+ case Z_OK: /* Do nothing */ break;
+ case Z_MEM_ERROR:
+ case Z_STREAM_ERROR: png_warning(png_ptr, "zlib memory error");
+ png_cleanup_needed = 1; break;
+ case Z_VERSION_ERROR: png_warning(png_ptr, "zlib version error");
+ png_cleanup_needed = 1; break;
+ default: png_warning(png_ptr, "Unknown zlib error");
+ png_cleanup_needed = 1;
+ }
+ }
+
+ if (png_cleanup_needed)
+ {
+ /* Clean up PNG structure and deallocate any memory. */
+ png_free(png_ptr, png_ptr->zbuf);
+ png_ptr->zbuf = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)png_ptr,
+ (png_free_ptr)free_fn, (png_voidp)mem_ptr);
+#else
+ png_destroy_struct((png_voidp)png_ptr);
+#endif
+ return (NULL);
+ }
+
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+
+ png_set_read_fn(png_ptr, NULL, NULL);
+
+
+ return (png_ptr);
+}
+
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the information before the actual image data. This has been
+ * changed in v0.90 to allow reading a file that already has the magic
+ * bytes read from the stream. You can tell libpng how many bytes have
+ * been read from the beginning of the stream (up to the maximum of 8)
+ * via png_set_sig_bytes(), and we will only check the remaining bytes
+ * here. The application can then have access to the signature bytes we
+ * read if it is determined that this isn't a valid PNG file.
+ */
+void PNGAPI
+png_read_info(png_structp png_ptr, png_infop info_ptr)
+{
+ png_debug(1, "in png_read_info");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* If we haven't checked all of the PNG signature bytes, do so now. */
+ if (png_ptr->sig_bytes < 8)
+ {
+ png_size_t num_checked = png_ptr->sig_bytes,
+ num_to_check = 8 - num_checked;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
+#endif
+
+ png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
+ png_ptr->sig_bytes = 8;
+
+ if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
+ {
+ if (num_checked < 4 &&
+ png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+ png_error(png_ptr, "Not a PNG file");
+ else
+ png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+ }
+ if (num_checked < 3)
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+ }
+
+ for (;;)
+ {
+ PNG_IHDR;
+ PNG_IDAT;
+ PNG_IEND;
+ PNG_PLTE;
+#ifdef PNG_READ_bKGD_SUPPORTED
+ PNG_bKGD;
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+ PNG_cHRM;
+#endif
+#ifdef PNG_READ_gAMA_SUPPORTED
+ PNG_gAMA;
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+ PNG_hIST;
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+ PNG_iCCP;
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+ PNG_iTXt;
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+ PNG_oFFs;
+#endif
+#ifdef PNG_READ_pCAL_SUPPORTED
+ PNG_pCAL;
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+ PNG_pHYs;
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+ PNG_sBIT;
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+ PNG_sCAL;
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+ PNG_sPLT;
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+ PNG_sRGB;
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+ PNG_tEXt;
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+ PNG_tIME;
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+ PNG_tRNS;
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+ PNG_zTXt;
+#endif
+ png_uint_32 length = png_read_chunk_header(png_ptr);
+ PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
+
+ /* This should be a binary subdivision search or a hash for
+ * matching the chunk name rather than a linear search.
+ */
+ if (!png_memcmp(chunk_name, png_IDAT, 4))
+ if (png_ptr->mode & PNG_AFTER_IDAT)
+ png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+ if (!png_memcmp(chunk_name, png_IHDR, 4))
+ png_handle_IHDR(png_ptr, info_ptr, length);
+ else if (!png_memcmp(chunk_name, png_IEND, 4))
+ png_handle_IEND(png_ptr, info_ptr, length);
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if (png_handle_as_unknown(png_ptr, chunk_name))
+ {
+ if (!png_memcmp(chunk_name, png_IDAT, 4))
+ png_ptr->mode |= PNG_HAVE_IDAT;
+ png_handle_unknown(png_ptr, info_ptr, length);
+ if (!png_memcmp(chunk_name, png_PLTE, 4))
+ png_ptr->mode |= PNG_HAVE_PLTE;
+ else if (!png_memcmp(chunk_name, png_IDAT, 4))
+ {
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before IDAT");
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ !(png_ptr->mode & PNG_HAVE_PLTE))
+ png_error(png_ptr, "Missing PLTE before IDAT");
+ break;
+ }
+ }
+#endif
+ else if (!png_memcmp(chunk_name, png_PLTE, 4))
+ png_handle_PLTE(png_ptr, info_ptr, length);
+ else if (!png_memcmp(chunk_name, png_IDAT, 4))
+ {
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before IDAT");
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ !(png_ptr->mode & PNG_HAVE_PLTE))
+ png_error(png_ptr, "Missing PLTE before IDAT");
+
+ png_ptr->idat_size = length;
+ png_ptr->mode |= PNG_HAVE_IDAT;
+ break;
+ }
+#ifdef PNG_READ_bKGD_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_bKGD, 4))
+ png_handle_bKGD(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_cHRM, 4))
+ png_handle_cHRM(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_gAMA_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_gAMA, 4))
+ png_handle_gAMA(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_hIST, 4))
+ png_handle_hIST(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_oFFs, 4))
+ png_handle_oFFs(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_pCAL_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_pCAL, 4))
+ png_handle_pCAL(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_sCAL, 4))
+ png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_pHYs, 4))
+ png_handle_pHYs(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_sBIT, 4))
+ png_handle_sBIT(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_sRGB, 4))
+ png_handle_sRGB(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_iCCP, 4))
+ png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_sPLT, 4))
+ png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_tEXt, 4))
+ png_handle_tEXt(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_tIME, 4))
+ png_handle_tIME(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_tRNS, 4))
+ png_handle_tRNS(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_zTXt, 4))
+ png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_iTXt, 4))
+ png_handle_iTXt(png_ptr, info_ptr, length);
+#endif
+ else
+ png_handle_unknown(png_ptr, info_ptr, length);
+ }
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+
+/* Optional call to update the users info_ptr structure */
+void PNGAPI
+png_read_update_info(png_structp png_ptr, png_infop info_ptr)
+{
+ png_debug(1, "in png_read_update_info");
+
+ if (png_ptr == NULL)
+ return;
+ if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
+ png_read_start_row(png_ptr);
+ else
+ png_warning(png_ptr,
+ "Ignoring extra png_read_update_info() call; row buffer not reallocated");
+
+ png_read_transform_info(png_ptr, info_ptr);
+}
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Initialize palette, background, etc, after transformations
+ * are set, but before any reading takes place. This allows
+ * the user to obtain a gamma-corrected palette, for example.
+ * If the user doesn't call this, we will do it ourselves.
+ */
+void PNGAPI
+png_start_read_image(png_structp png_ptr)
+{
+ png_debug(1, "in png_start_read_image");
+
+ if (png_ptr == NULL)
+ return;
+ if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
+ png_read_start_row(png_ptr);
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+void PNGAPI
+png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
+{
+ PNG_IDAT;
+ PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
+ 0xff};
+ PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
+ int ret;
+
+ if (png_ptr == NULL)
+ return;
+
+ png_debug2(1, "in png_read_row (row %lu, pass %d)",
+ (unsigned long) png_ptr->row_number, png_ptr->pass);
+
+ if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
+ png_read_start_row(png_ptr);
+ if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+ {
+ /* Check for transforms that have been set but were defined out */
+#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
+ if (png_ptr->transformations & PNG_INVERT_MONO)
+ png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
+ if (png_ptr->transformations & PNG_FILLER)
+ png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
+ !defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACK)
+ png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
+ if (png_ptr->transformations & PNG_SHIFT)
+ png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
+ if (png_ptr->transformations & PNG_BGR)
+ png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_SWAP_BYTES)
+ png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined");
+#endif
+ }
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* If interlaced and we do not need a new row, combine row and return */
+ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+ {
+ switch (png_ptr->pass)
+ {
+ case 0:
+ if (png_ptr->row_number & 0x07)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row,
+ png_pass_dsp_mask[png_ptr->pass]);
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 1:
+ if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row,
+ png_pass_dsp_mask[png_ptr->pass]);
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 2:
+ if ((png_ptr->row_number & 0x07) != 4)
+ {
+ if (dsp_row != NULL && (png_ptr->row_number & 4))
+ png_combine_row(png_ptr, dsp_row,
+ png_pass_dsp_mask[png_ptr->pass]);
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 3:
+ if ((png_ptr->row_number & 3) || png_ptr->width < 3)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row,
+ png_pass_dsp_mask[png_ptr->pass]);
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 4:
+ if ((png_ptr->row_number & 3) != 2)
+ {
+ if (dsp_row != NULL && (png_ptr->row_number & 2))
+ png_combine_row(png_ptr, dsp_row,
+ png_pass_dsp_mask[png_ptr->pass]);
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 5:
+ if ((png_ptr->row_number & 1) || png_ptr->width < 2)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row,
+ png_pass_dsp_mask[png_ptr->pass]);
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 6:
+ if (!(png_ptr->row_number & 1))
+ {
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+ }
+ }
+#endif
+
+ if (!(png_ptr->mode & PNG_HAVE_IDAT))
+ png_error(png_ptr, "Invalid attempt to read row data");
+
+ png_ptr->zstream.next_out = png_ptr->row_buf;
+ png_ptr->zstream.avail_out =
+ (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
+ png_ptr->iwidth) + 1);
+ do
+ {
+ if (!(png_ptr->zstream.avail_in))
+ {
+ while (!png_ptr->idat_size)
+ {
+ png_crc_finish(png_ptr, 0);
+
+ png_ptr->idat_size = png_read_chunk_header(png_ptr);
+ if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ png_error(png_ptr, "Not enough image data");
+ }
+ png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
+ png_ptr->zstream.next_in = png_ptr->zbuf;
+ if (png_ptr->zbuf_size > png_ptr->idat_size)
+ png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
+ png_crc_read(png_ptr, png_ptr->zbuf,
+ (png_size_t)png_ptr->zstream.avail_in);
+ png_ptr->idat_size -= png_ptr->zstream.avail_in;
+ }
+ ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+ if (ret == Z_STREAM_END)
+ {
+ if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
+ png_ptr->idat_size)
+ png_benign_error(png_ptr, "Extra compressed data");
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ break;
+ }
+ if (ret != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
+ "Decompression error");
+
+ } while (png_ptr->zstream.avail_out);
+
+ png_ptr->row_info.color_type = png_ptr->color_type;
+ png_ptr->row_info.width = png_ptr->iwidth;
+ png_ptr->row_info.channels = png_ptr->channels;
+ png_ptr->row_info.bit_depth = png_ptr->bit_depth;
+ png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
+ png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
+ png_ptr->row_info.width);
+
+ if (png_ptr->row_buf[0])
+ png_read_filter_row(png_ptr, &(png_ptr->row_info),
+ png_ptr->row_buf + 1, png_ptr->prev_row + 1,
+ (int)(png_ptr->row_buf[0]));
+
+ png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+ (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+ {
+ /* Intrapixel differencing */
+ png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
+ }
+#endif
+
+
+ if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
+ png_do_read_transformations(png_ptr);
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Blow up interlaced rows to full size */
+ if (png_ptr->interlaced &&
+ (png_ptr->transformations & PNG_INTERLACE))
+ {
+ if (png_ptr->pass < 6)
+ /* Old interface (pre-1.0.9):
+ * png_do_read_interlace(&(png_ptr->row_info),
+ * png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
+ */
+ png_do_read_interlace(png_ptr);
+
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row,
+ png_pass_dsp_mask[png_ptr->pass]);
+ if (row != NULL)
+ png_combine_row(png_ptr, row,
+ png_pass_mask[png_ptr->pass]);
+ }
+ else
+#endif
+ {
+ if (row != NULL)
+ png_combine_row(png_ptr, row, 0xff);
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, 0xff);
+ }
+ png_read_finish_row(png_ptr);
+
+ if (png_ptr->read_row_fn != NULL)
+ (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read one or more rows of image data. If the image is interlaced,
+ * and png_set_interlace_handling() has been called, the rows need to
+ * contain the contents of the rows from the previous pass. If the
+ * image has alpha or transparency, and png_handle_alpha()[*] has been
+ * called, the rows contents must be initialized to the contents of the
+ * screen.
+ *
+ * "row" holds the actual image, and pixels are placed in it
+ * as they arrive. If the image is displayed after each pass, it will
+ * appear to "sparkle" in. "display_row" can be used to display a
+ * "chunky" progressive image, with finer detail added as it becomes
+ * available. If you do not want this "chunky" display, you may pass
+ * NULL for display_row. If you do not want the sparkle display, and
+ * you have not called png_handle_alpha(), you may pass NULL for rows.
+ * If you have called png_handle_alpha(), and the image has either an
+ * alpha channel or a transparency chunk, you must provide a buffer for
+ * rows. In this case, you do not have to provide a display_row buffer
+ * also, but you may. If the image is not interlaced, or if you have
+ * not called png_set_interlace_handling(), the display_row buffer will
+ * be ignored, so pass NULL to it.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng
+ */
+
+void PNGAPI
+png_read_rows(png_structp png_ptr, png_bytepp row,
+ png_bytepp display_row, png_uint_32 num_rows)
+{
+ png_uint_32 i;
+ png_bytepp rp;
+ png_bytepp dp;
+
+ png_debug(1, "in png_read_rows");
+
+ if (png_ptr == NULL)
+ return;
+ rp = row;
+ dp = display_row;
+ if (rp != NULL && dp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep rptr = *rp++;
+ png_bytep dptr = *dp++;
+
+ png_read_row(png_ptr, rptr, dptr);
+ }
+ else if (rp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep rptr = *rp;
+ png_read_row(png_ptr, rptr, NULL);
+ rp++;
+ }
+ else if (dp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep dptr = *dp;
+ png_read_row(png_ptr, NULL, dptr);
+ dp++;
+ }
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the entire image. If the image has an alpha channel or a tRNS
+ * chunk, and you have called png_handle_alpha()[*], you will need to
+ * initialize the image to the current image that PNG will be overlaying.
+ * We set the num_rows again here, in case it was incorrectly set in
+ * png_read_start_row() by a call to png_read_update_info() or
+ * png_start_read_image() if png_set_interlace_handling() wasn't called
+ * prior to either of these functions like it should have been. You can
+ * only call this function once. If you desire to have an image for
+ * each pass of a interlaced image, use png_read_rows() instead.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng
+ */
+void PNGAPI
+png_read_image(png_structp png_ptr, png_bytepp image)
+{
+ png_uint_32 i, image_height;
+ int pass, j;
+ png_bytepp rp;
+
+ png_debug(1, "in png_read_image");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ pass = png_set_interlace_handling(png_ptr);
+#else
+ if (png_ptr->interlaced)
+ png_error(png_ptr,
+ "Cannot read interlaced image -- interlace handler disabled");
+ pass = 1;
+#endif
+
+
+ image_height=png_ptr->height;
+ png_ptr->num_rows = image_height; /* Make sure this is set correctly */
+
+ for (j = 0; j < pass; j++)
+ {
+ rp = image;
+ for (i = 0; i < image_height; i++)
+ {
+ png_read_row(png_ptr, *rp, NULL);
+ rp++;
+ }
+ }
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the end of the PNG file. Will not read past the end of the
+ * file, will verify the end is accurate, and will read any comments
+ * or time information at the end of the file, if info is not NULL.
+ */
+void PNGAPI
+png_read_end(png_structp png_ptr, png_infop info_ptr)
+{
+ png_debug(1, "in png_read_end");
+
+ if (png_ptr == NULL)
+ return;
+ png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
+
+ do
+ {
+ PNG_IHDR;
+ PNG_IDAT;
+ PNG_IEND;
+ PNG_PLTE;
+#ifdef PNG_READ_bKGD_SUPPORTED
+ PNG_bKGD;
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+ PNG_cHRM;
+#endif
+#ifdef PNG_READ_gAMA_SUPPORTED
+ PNG_gAMA;
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+ PNG_hIST;
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+ PNG_iCCP;
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+ PNG_iTXt;
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+ PNG_oFFs;
+#endif
+#ifdef PNG_READ_pCAL_SUPPORTED
+ PNG_pCAL;
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+ PNG_pHYs;
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+ PNG_sBIT;
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+ PNG_sCAL;
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+ PNG_sPLT;
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+ PNG_sRGB;
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+ PNG_tEXt;
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+ PNG_tIME;
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+ PNG_tRNS;
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+ PNG_zTXt;
+#endif
+ png_uint_32 length = png_read_chunk_header(png_ptr);
+ PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
+
+ if (!png_memcmp(chunk_name, png_IHDR, 4))
+ png_handle_IHDR(png_ptr, info_ptr, length);
+ else if (!png_memcmp(chunk_name, png_IEND, 4))
+ png_handle_IEND(png_ptr, info_ptr, length);
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if (png_handle_as_unknown(png_ptr, chunk_name))
+ {
+ if (!png_memcmp(chunk_name, png_IDAT, 4))
+ {
+ if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+ png_benign_error(png_ptr, "Too many IDATs found");
+ }
+ png_handle_unknown(png_ptr, info_ptr, length);
+ if (!png_memcmp(chunk_name, png_PLTE, 4))
+ png_ptr->mode |= PNG_HAVE_PLTE;
+ }
+#endif
+ else if (!png_memcmp(chunk_name, png_IDAT, 4))
+ {
+ /* Zero length IDATs are legal after the last IDAT has been
+ * read, but not after other chunks have been read.
+ */
+ if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+ png_benign_error(png_ptr, "Too many IDATs found");
+ png_crc_finish(png_ptr, length);
+ }
+ else if (!png_memcmp(chunk_name, png_PLTE, 4))
+ png_handle_PLTE(png_ptr, info_ptr, length);
+#ifdef PNG_READ_bKGD_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_bKGD, 4))
+ png_handle_bKGD(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_cHRM, 4))
+ png_handle_cHRM(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_gAMA_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_gAMA, 4))
+ png_handle_gAMA(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_hIST, 4))
+ png_handle_hIST(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_oFFs, 4))
+ png_handle_oFFs(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_pCAL_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_pCAL, 4))
+ png_handle_pCAL(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_sCAL, 4))
+ png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_pHYs, 4))
+ png_handle_pHYs(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_sBIT, 4))
+ png_handle_sBIT(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_sRGB, 4))
+ png_handle_sRGB(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_iCCP, 4))
+ png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_sPLT, 4))
+ png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_tEXt, 4))
+ png_handle_tEXt(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_tIME, 4))
+ png_handle_tIME(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_tRNS, 4))
+ png_handle_tRNS(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_zTXt, 4))
+ png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+ else if (!png_memcmp(chunk_name, png_iTXt, 4))
+ png_handle_iTXt(png_ptr, info_ptr, length);
+#endif
+ else
+ png_handle_unknown(png_ptr, info_ptr, length);
+ } while (!(png_ptr->mode & PNG_HAVE_IEND));
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+
+/* Free all memory used by the read */
+void PNGAPI
+png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
+ png_infopp end_info_ptr_ptr)
+{
+ png_structp png_ptr = NULL;
+ png_infop info_ptr = NULL, end_info_ptr = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_free_ptr free_fn = NULL;
+ png_voidp mem_ptr = NULL;
+#endif
+
+ png_debug(1, "in png_destroy_read_struct");
+
+ if (png_ptr_ptr != NULL)
+ png_ptr = *png_ptr_ptr;
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ free_fn = png_ptr->free_fn;
+ mem_ptr = png_ptr->mem_ptr;
+#endif
+
+ if (info_ptr_ptr != NULL)
+ info_ptr = *info_ptr_ptr;
+
+ if (end_info_ptr_ptr != NULL)
+ end_info_ptr = *end_info_ptr_ptr;
+
+ png_read_destroy(png_ptr, info_ptr, end_info_ptr);
+
+ if (info_ptr != NULL)
+ {
+#ifdef PNG_TEXT_SUPPORTED
+ png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
+#endif
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
+ (png_voidp)mem_ptr);
+#else
+ png_destroy_struct((png_voidp)info_ptr);
+#endif
+ *info_ptr_ptr = NULL;
+ }
+
+ if (end_info_ptr != NULL)
+ {
+#ifdef PNG_READ_TEXT_SUPPORTED
+ png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
+#endif
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
+ (png_voidp)mem_ptr);
+#else
+ png_destroy_struct((png_voidp)end_info_ptr);
+#endif
+ *end_info_ptr_ptr = NULL;
+ }
+
+ if (png_ptr != NULL)
+ {
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
+ (png_voidp)mem_ptr);
+#else
+ png_destroy_struct((png_voidp)png_ptr);
+#endif
+ *png_ptr_ptr = NULL;
+ }
+}
+
+/* Free all memory used by the read (old method) */
+void /* PRIVATE */
+png_read_destroy(png_structp png_ptr, png_infop info_ptr,
+ png_infop end_info_ptr)
+{
+#ifdef PNG_SETJMP_SUPPORTED
+ jmp_buf tmp_jmp;
+#endif
+ png_error_ptr error_fn;
+ png_error_ptr warning_fn;
+ png_voidp error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_free_ptr free_fn;
+#endif
+
+ png_debug(1, "in png_read_destroy");
+
+ if (info_ptr != NULL)
+ png_info_destroy(png_ptr, info_ptr);
+
+ if (end_info_ptr != NULL)
+ png_info_destroy(png_ptr, end_info_ptr);
+
+ png_free(png_ptr, png_ptr->zbuf);
+ png_free(png_ptr, png_ptr->big_row_buf);
+ png_free(png_ptr, png_ptr->prev_row);
+ png_free(png_ptr, png_ptr->chunkdata);
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ png_free(png_ptr, png_ptr->palette_lookup);
+ png_free(png_ptr, png_ptr->quantize_index);
+#endif
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ png_free(png_ptr, png_ptr->gamma_table);
+#endif
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ png_free(png_ptr, png_ptr->gamma_from_1);
+ png_free(png_ptr, png_ptr->gamma_to_1);
+#endif
+ if (png_ptr->free_me & PNG_FREE_PLTE)
+ png_zfree(png_ptr, png_ptr->palette);
+ png_ptr->free_me &= ~PNG_FREE_PLTE;
+#if defined(PNG_tRNS_SUPPORTED) || \
+ defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->free_me & PNG_FREE_TRNS)
+ png_free(png_ptr, png_ptr->trans_alpha);
+ png_ptr->free_me &= ~PNG_FREE_TRNS;
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+ if (png_ptr->free_me & PNG_FREE_HIST)
+ png_free(png_ptr, png_ptr->hist);
+ png_ptr->free_me &= ~PNG_FREE_HIST;
+#endif
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (png_ptr->gamma_16_table != NULL)
+ {
+ int i;
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
+ {
+ png_free(png_ptr, png_ptr->gamma_16_table[i]);
+ }
+ png_free(png_ptr, png_ptr->gamma_16_table);
+ }
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ if (png_ptr->gamma_16_from_1 != NULL)
+ {
+ int i;
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
+ {
+ png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
+ }
+ png_free(png_ptr, png_ptr->gamma_16_from_1);
+ }
+ if (png_ptr->gamma_16_to_1 != NULL)
+ {
+ int i;
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
+ {
+ png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
+ }
+ png_free(png_ptr, png_ptr->gamma_16_to_1);
+ }
+#endif
+#endif
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+ png_free(png_ptr, png_ptr->time_buffer);
+#endif
+
+ inflateEnd(&png_ptr->zstream);
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+ png_free(png_ptr, png_ptr->save_buffer);
+#endif
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+#ifdef PNG_TEXT_SUPPORTED
+ png_free(png_ptr, png_ptr->current_text);
+#endif /* PNG_TEXT_SUPPORTED */
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+
+ /* Save the important info out of the png_struct, in case it is
+ * being used again.
+ */
+#ifdef PNG_SETJMP_SUPPORTED
+ png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
+#endif
+
+ error_fn = png_ptr->error_fn;
+ warning_fn = png_ptr->warning_fn;
+ error_ptr = png_ptr->error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ free_fn = png_ptr->free_fn;
+#endif
+
+ png_memset(png_ptr, 0, png_sizeof(png_struct));
+
+ png_ptr->error_fn = error_fn;
+ png_ptr->warning_fn = warning_fn;
+ png_ptr->error_ptr = error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_ptr->free_fn = free_fn;
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+ png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
+#endif
+
+}
+
+void PNGAPI
+png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
+{
+ if (png_ptr == NULL)
+ return;
+ png_ptr->read_row_fn = read_row_fn;
+}
+
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_read_png(png_structp png_ptr, png_infop info_ptr,
+ int transforms,
+ voidp params)
+{
+ int row;
+
+ if (png_ptr == NULL)
+ return;
+
+ /* png_read_info() gives us all of the information from the
+ * PNG file before the first IDAT (image data chunk).
+ */
+ png_read_info(png_ptr, info_ptr);
+ if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+ png_error(png_ptr, "Image is too high to process with png_read_png()");
+
+ /* -------------- image transformations start here ------------------- */
+
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+ /* Tell libpng to strip 16 bit/color files down to 8 bits per color.
+ */
+ if (transforms & PNG_TRANSFORM_STRIP_16)
+ png_set_strip_16(png_ptr);
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ /* Strip alpha bytes from the input data without combining with
+ * the background (not recommended).
+ */
+ if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
+ png_set_strip_alpha(png_ptr);
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
+ /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
+ * byte into separate bytes (useful for paletted and grayscale images).
+ */
+ if (transforms & PNG_TRANSFORM_PACKING)
+ png_set_packing(png_ptr);
+#endif
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ /* Change the order of packed pixels to least significant bit first
+ * (not useful if you are using png_set_packing).
+ */
+ if (transforms & PNG_TRANSFORM_PACKSWAP)
+ png_set_packswap(png_ptr);
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ /* Expand paletted colors into true RGB triplets
+ * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
+ * Expand paletted or RGB images with transparency to full alpha
+ * channels so the data will be available as RGBA quartets.
+ */
+ if (transforms & PNG_TRANSFORM_EXPAND)
+ if ((png_ptr->bit_depth < 8) ||
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
+ (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
+ png_set_expand(png_ptr);
+#endif
+
+ /* We don't handle background color or gamma transformation or quantizing.
+ */
+
+#ifdef PNG_READ_INVERT_SUPPORTED
+ /* Invert monochrome files to have 0 as white and 1 as black
+ */
+ if (transforms & PNG_TRANSFORM_INVERT_MONO)
+ png_set_invert_mono(png_ptr);
+#endif
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+ /* If you want to shift the pixel values from the range [0,255] or
+ * [0,65535] to the original [0,7] or [0,31], or whatever range the
+ * colors were originally in:
+ */
+ if ((transforms & PNG_TRANSFORM_SHIFT)
+ && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
+ {
+ png_color_8p sig_bit;
+
+ png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+ png_set_shift(png_ptr, sig_bit);
+ }
+#endif
+
+#ifdef PNG_READ_BGR_SUPPORTED
+ /* Flip the RGB pixels to BGR (or RGBA to BGRA)
+ */
+ if (transforms & PNG_TRANSFORM_BGR)
+ png_set_bgr(png_ptr);
+#endif
+
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+ /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR)
+ */
+ if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+ png_set_swap_alpha(png_ptr);
+#endif
+
+#ifdef PNG_READ_SWAP_SUPPORTED
+ /* Swap bytes of 16 bit files to least significant byte first
+ */
+ if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+ png_set_swap(png_ptr);
+#endif
+
+/* Added at libpng-1.2.41 */
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+ /* Invert the alpha channel from opacity to transparency
+ */
+ if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+ png_set_invert_alpha(png_ptr);
+#endif
+
+/* Added at libpng-1.2.41 */
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* Expand grayscale image to RGB
+ */
+ if (transforms & PNG_TRANSFORM_GRAY_TO_RGB)
+ png_set_gray_to_rgb(png_ptr);
+#endif
+
+ /* We don't handle adding filler bytes */
+
+ /* Optional call to gamma correct and add the background to the palette
+ * and update info structure. REQUIRED if you are expecting libpng to
+ * update the palette for you (i.e., you selected such a transform above).
+ */
+ png_read_update_info(png_ptr, info_ptr);
+
+ /* -------------- image transformations end here ------------------- */
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+ if (info_ptr->row_pointers == NULL)
+ {
+ png_uint_32 iptr;
+
+ info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
+ info_ptr->height * png_sizeof(png_bytep));
+ for (iptr=0; iptr<info_ptr->height; iptr++)
+ info_ptr->row_pointers[iptr] = NULL;
+
+ info_ptr->free_me |= PNG_FREE_ROWS;
+
+ for (row = 0; row < (int)info_ptr->height; row++)
+ info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
+ png_get_rowbytes(png_ptr, info_ptr));
+ }
+
+ png_read_image(png_ptr, info_ptr->row_pointers);
+ info_ptr->valid |= PNG_INFO_IDAT;
+
+ /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
+ png_read_end(png_ptr, info_ptr);
+
+ transforms = transforms; /* Quiet compiler warnings */
+ params = params;
+
+}
+#endif /* PNG_INFO_IMAGE_SUPPORTED */
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED */
--- /dev/null
+
+/* pngrio.c - functions for data input
+ *
+ * Last changed in libpng 1.4.1 [February 25, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all input. Users who need
+ * special handling are expected to write a function that has the same
+ * arguments as this and performs a similar function, but that possibly
+ * has a different input method. Note that you shouldn't change this
+ * function, but rather write a replacement function and then make
+ * libpng use it at run time with png_set_read_fn(...).
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#ifdef PNG_READ_SUPPORTED
+#include "pngpriv.h"
+
+/* Read the data from whatever input you are using. The default routine
+ * reads from a file pointer. Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered reads. This should never be asked
+ * to read more then 64K on a 16 bit machine.
+ */
+void /* PRIVATE */
+png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+ png_debug1(4, "reading %d bytes", (int)length);
+
+ if (png_ptr->read_data_fn != NULL)
+ (*(png_ptr->read_data_fn))(png_ptr, data, length);
+ else
+ png_error(png_ptr, "Call to NULL read function");
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual reading of data. If you are
+ * not reading from a standard C stream, you should create a replacement
+ * read_data function and use it at run time with png_set_read_fn(), rather
+ * than changing the library.
+ */
+#ifndef USE_FAR_KEYWORD
+void PNGAPI
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+ png_size_t check;
+
+ if (png_ptr == NULL)
+ return;
+ /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+ * instead of an int, which is what fread() actually returns.
+ */
+ check = fread(data, 1, length, (png_FILE_p)png_ptr->io_ptr);
+
+ if (check != length)
+ png_error(png_ptr, "Read Error");
+}
+#else
+/* This is the model-independent version. Since the standard I/O library
+ can't handle far buffers in the medium and small models, we have to copy
+ the data.
+*/
+
+#define NEAR_BUF_SIZE 1024
+#define MIN(a,b) (a <= b ? a : b)
+
+static void PNGAPI
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+ png_size_t check;
+ png_byte *n_data;
+ png_FILE_p io_ptr;
+
+ if (png_ptr == NULL)
+ return;
+ /* Check if data really is near. If so, use usual code. */
+ n_data = (png_byte *)CVT_PTR_NOCHECK(data);
+ io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
+ if ((png_bytep)n_data == data)
+ {
+ check = fread(n_data, 1, length, io_ptr);
+ }
+ else
+ {
+ png_byte buf[NEAR_BUF_SIZE];
+ png_size_t read, remaining, err;
+ check = 0;
+ remaining = length;
+ do
+ {
+ read = MIN(NEAR_BUF_SIZE, remaining);
+ err = fread(buf, 1, read, io_ptr);
+ png_memcpy(data, buf, read); /* copy far buffer to near buffer */
+ if (err != read)
+ break;
+ else
+ check += err;
+ data += read;
+ remaining -= read;
+ }
+ while (remaining != 0);
+ }
+ if ((png_uint_32)check != (png_uint_32)length)
+ png_error(png_ptr, "read Error");
+}
+#endif
+#endif
+
+/* This function allows the application to supply a new input function
+ * for libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ * png_ptr - pointer to a png input data structure
+ * io_ptr - pointer to user supplied structure containing info about
+ * the input functions. May be NULL.
+ * read_data_fn - pointer to a new input function that takes as its
+ * arguments a pointer to a png_struct, a pointer to
+ * a location where input data can be stored, and a 32-bit
+ * unsigned int that is the number of bytes to be read.
+ * To exit and output any fatal error messages the new write
+ * function should call png_error(png_ptr, "Error msg").
+ * May be NULL, in which case libpng's default function will
+ * be used.
+ */
+void PNGAPI
+png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
+ png_rw_ptr read_data_fn)
+{
+ if (png_ptr == NULL)
+ return;
+ png_ptr->io_ptr = io_ptr;
+
+#ifdef PNG_STDIO_SUPPORTED
+ if (read_data_fn != NULL)
+ png_ptr->read_data_fn = read_data_fn;
+ else
+ png_ptr->read_data_fn = png_default_read_data;
+#else
+ png_ptr->read_data_fn = read_data_fn;
+#endif
+
+ /* It is an error to write to a read device */
+ if (png_ptr->write_data_fn != NULL)
+ {
+ png_ptr->write_data_fn = NULL;
+ png_warning(png_ptr,
+ "It's an error to set both read_data_fn and write_data_fn in the ");
+ png_warning(png_ptr,
+ "same structure. Resetting write_data_fn to NULL");
+ }
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+ png_ptr->output_flush_fn = NULL;
+#endif
+}
+#endif /* PNG_READ_SUPPORTED */
--- /dev/null
+
+/* pngrtran.c - transforms the data in a row for PNG readers
+ *
+ * Last changed in libpng 1.4.2 [May 6, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains functions optionally called by an application
+ * in order to tell libpng how to handle data when reading a PNG.
+ * Transformations that are used in both reading and writing are
+ * in pngtrans.c.
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#ifdef PNG_READ_SUPPORTED
+#include "pngpriv.h"
+
+/* Set the action on getting a CRC error for an ancillary or critical chunk. */
+void PNGAPI
+png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
+{
+ png_debug(1, "in png_set_crc_action");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* Tell libpng how we react to CRC errors in critical chunks */
+ switch (crit_action)
+ {
+ case PNG_CRC_NO_CHANGE: /* Leave setting as is */
+ break;
+
+ case PNG_CRC_WARN_USE: /* Warn/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
+ break;
+
+ case PNG_CRC_QUIET_USE: /* Quiet/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
+ PNG_FLAG_CRC_CRITICAL_IGNORE;
+ break;
+
+ case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */
+ png_warning(png_ptr,
+ "Can't discard critical data on CRC error");
+ case PNG_CRC_ERROR_QUIT: /* Error/quit */
+
+ case PNG_CRC_DEFAULT:
+ default:
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ break;
+ }
+
+ /* Tell libpng how we react to CRC errors in ancillary chunks */
+ switch (ancil_action)
+ {
+ case PNG_CRC_NO_CHANGE: /* Leave setting as is */
+ break;
+
+ case PNG_CRC_WARN_USE: /* Warn/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
+ break;
+
+ case PNG_CRC_QUIET_USE: /* Quiet/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
+ PNG_FLAG_CRC_ANCILLARY_NOWARN;
+ break;
+
+ case PNG_CRC_ERROR_QUIT: /* Error/quit */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
+ break;
+
+ case PNG_CRC_WARN_DISCARD: /* Warn/discard data */
+
+ case PNG_CRC_DEFAULT:
+ default:
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ break;
+ }
+}
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+ defined(PNG_FLOATING_POINT_SUPPORTED)
+/* Handle alpha and tRNS via a background color */
+void PNGAPI
+png_set_background(png_structp png_ptr,
+ png_color_16p background_color, int background_gamma_code,
+ int need_expand, double background_gamma)
+{
+ png_debug(1, "in png_set_background");
+
+ if (png_ptr == NULL)
+ return;
+ if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
+ {
+ png_warning(png_ptr, "Application must supply a known background gamma");
+ return;
+ }
+
+ png_ptr->transformations |= PNG_BACKGROUND;
+ png_memcpy(&(png_ptr->background), background_color,
+ png_sizeof(png_color_16));
+ png_ptr->background_gamma = (float)background_gamma;
+ png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
+ png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0);
+}
+#endif
+
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+/* Strip 16 bit depth files to 8 bit depth */
+void PNGAPI
+png_set_strip_16(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_strip_16");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->transformations |= PNG_16_TO_8;
+}
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+void PNGAPI
+png_set_strip_alpha(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_strip_alpha");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->flags |= PNG_FLAG_STRIP_ALPHA;
+}
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Quantize file to 8 bit. Supply a palette, the current number
+ * of elements in the palette, the maximum number of elements
+ * allowed, and a histogram if possible. If the current number
+ * of colors is greater then the maximum number, the palette will be
+ * modified to fit in the maximum number. "full_quantize" indicates
+ * whether we need a quantizeing cube set up for RGB images, or if we
+ * simply are reducing the number of colors in a paletted image.
+ */
+
+typedef struct png_dsort_struct
+{
+ struct png_dsort_struct FAR * next;
+ png_byte left;
+ png_byte right;
+} png_dsort;
+typedef png_dsort FAR * png_dsortp;
+typedef png_dsort FAR * FAR * png_dsortpp;
+
+void PNGAPI
+png_set_quantize(png_structp png_ptr, png_colorp palette,
+ int num_palette, int maximum_colors, png_uint_16p histogram,
+ int full_quantize)
+{
+ png_debug(1, "in png_set_quantize");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->transformations |= PNG_QUANTIZE;
+
+ if (!full_quantize)
+ {
+ int i;
+
+ png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * png_sizeof(png_byte)));
+ for (i = 0; i < num_palette; i++)
+ png_ptr->quantize_index[i] = (png_byte)i;
+ }
+
+ if (num_palette > maximum_colors)
+ {
+ if (histogram != NULL)
+ {
+ /* This is easy enough, just throw out the least used colors.
+ * Perhaps not the best solution, but good enough.
+ */
+
+ int i;
+
+ /* Initialize an array to sort colors */
+ png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * png_sizeof(png_byte)));
+
+ /* Initialize the quantize_sort array */
+ for (i = 0; i < num_palette; i++)
+ png_ptr->quantize_sort[i] = (png_byte)i;
+
+ /* Find the least used palette entries by starting a
+ * bubble sort, and running it until we have sorted
+ * out enough colors. Note that we don't care about
+ * sorting all the colors, just finding which are
+ * least used.
+ */
+
+ for (i = num_palette - 1; i >= maximum_colors; i--)
+ {
+ int done; /* To stop early if the list is pre-sorted */
+ int j;
+
+ done = 1;
+ for (j = 0; j < i; j++)
+ {
+ if (histogram[png_ptr->quantize_sort[j]]
+ < histogram[png_ptr->quantize_sort[j + 1]])
+ {
+ png_byte t;
+
+ t = png_ptr->quantize_sort[j];
+ png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1];
+ png_ptr->quantize_sort[j + 1] = t;
+ done = 0;
+ }
+ }
+ if (done)
+ break;
+ }
+
+ /* Swap the palette around, and set up a table, if necessary */
+ if (full_quantize)
+ {
+ int j = num_palette;
+
+ /* Put all the useful colors within the max, but don't
+ * move the others.
+ */
+ for (i = 0; i < maximum_colors; i++)
+ {
+ if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+ {
+ do
+ j--;
+ while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+ palette[i] = palette[j];
+ }
+ }
+ }
+ else
+ {
+ int j = num_palette;
+
+ /* Move all the used colors inside the max limit, and
+ * develop a translation table.
+ */
+ for (i = 0; i < maximum_colors; i++)
+ {
+ /* Only move the colors we need to */
+ if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+ {
+ png_color tmp_color;
+
+ do
+ j--;
+ while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+
+ tmp_color = palette[j];
+ palette[j] = palette[i];
+ palette[i] = tmp_color;
+ /* Indicate where the color went */
+ png_ptr->quantize_index[j] = (png_byte)i;
+ png_ptr->quantize_index[i] = (png_byte)j;
+ }
+ }
+
+ /* Find closest color for those colors we are not using */
+ for (i = 0; i < num_palette; i++)
+ {
+ if ((int)png_ptr->quantize_index[i] >= maximum_colors)
+ {
+ int min_d, k, min_k, d_index;
+
+ /* Find the closest color to one we threw out */
+ d_index = png_ptr->quantize_index[i];
+ min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
+ for (k = 1, min_k = 0; k < maximum_colors; k++)
+ {
+ int d;
+
+ d = PNG_COLOR_DIST(palette[d_index], palette[k]);
+
+ if (d < min_d)
+ {
+ min_d = d;
+ min_k = k;
+ }
+ }
+ /* Point to closest color */
+ png_ptr->quantize_index[i] = (png_byte)min_k;
+ }
+ }
+ }
+ png_free(png_ptr, png_ptr->quantize_sort);
+ png_ptr->quantize_sort = NULL;
+ }
+ else
+ {
+ /* This is much harder to do simply (and quickly). Perhaps
+ * we need to go through a median cut routine, but those
+ * don't always behave themselves with only a few colors
+ * as input. So we will just find the closest two colors,
+ * and throw out one of them (chosen somewhat randomly).
+ * [We don't understand this at all, so if someone wants to
+ * work on improving it, be our guest - AED, GRP]
+ */
+ int i;
+ int max_d;
+ int num_new_palette;
+ png_dsortp t;
+ png_dsortpp hash;
+
+ t = NULL;
+
+ /* Initialize palette index arrays */
+ png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * png_sizeof(png_byte)));
+ png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * png_sizeof(png_byte)));
+
+ /* Initialize the sort array */
+ for (i = 0; i < num_palette; i++)
+ {
+ png_ptr->index_to_palette[i] = (png_byte)i;
+ png_ptr->palette_to_index[i] = (png_byte)i;
+ }
+
+ hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 *
+ png_sizeof(png_dsortp)));
+
+ num_new_palette = num_palette;
+
+ /* Initial wild guess at how far apart the farthest pixel
+ * pair we will be eliminating will be. Larger
+ * numbers mean more areas will be allocated, Smaller
+ * numbers run the risk of not saving enough data, and
+ * having to do this all over again.
+ *
+ * I have not done extensive checking on this number.
+ */
+ max_d = 96;
+
+ while (num_new_palette > maximum_colors)
+ {
+ for (i = 0; i < num_new_palette - 1; i++)
+ {
+ int j;
+
+ for (j = i + 1; j < num_new_palette; j++)
+ {
+ int d;
+
+ d = PNG_COLOR_DIST(palette[i], palette[j]);
+
+ if (d <= max_d)
+ {
+
+ t = (png_dsortp)png_malloc_warn(png_ptr,
+ (png_uint_32)(png_sizeof(png_dsort)));
+ if (t == NULL)
+ break;
+ t->next = hash[d];
+ t->left = (png_byte)i;
+ t->right = (png_byte)j;
+ hash[d] = t;
+ }
+ }
+ if (t == NULL)
+ break;
+ }
+
+ if (t != NULL)
+ for (i = 0; i <= max_d; i++)
+ {
+ if (hash[i] != NULL)
+ {
+ png_dsortp p;
+
+ for (p = hash[i]; p; p = p->next)
+ {
+ if ((int)png_ptr->index_to_palette[p->left]
+ < num_new_palette &&
+ (int)png_ptr->index_to_palette[p->right]
+ < num_new_palette)
+ {
+ int j, next_j;
+
+ if (num_new_palette & 0x01)
+ {
+ j = p->left;
+ next_j = p->right;
+ }
+ else
+ {
+ j = p->right;
+ next_j = p->left;
+ }
+
+ num_new_palette--;
+ palette[png_ptr->index_to_palette[j]]
+ = palette[num_new_palette];
+ if (!full_quantize)
+ {
+ int k;
+
+ for (k = 0; k < num_palette; k++)
+ {
+ if (png_ptr->quantize_index[k] ==
+ png_ptr->index_to_palette[j])
+ png_ptr->quantize_index[k] =
+ png_ptr->index_to_palette[next_j];
+ if ((int)png_ptr->quantize_index[k] ==
+ num_new_palette)
+ png_ptr->quantize_index[k] =
+ png_ptr->index_to_palette[j];
+ }
+ }
+
+ png_ptr->index_to_palette[png_ptr->palette_to_index
+ [num_new_palette]] = png_ptr->index_to_palette[j];
+ png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
+ = png_ptr->palette_to_index[num_new_palette];
+
+ png_ptr->index_to_palette[j] =
+ (png_byte)num_new_palette;
+ png_ptr->palette_to_index[num_new_palette] =
+ (png_byte)j;
+ }
+ if (num_new_palette <= maximum_colors)
+ break;
+ }
+ if (num_new_palette <= maximum_colors)
+ break;
+ }
+ }
+
+ for (i = 0; i < 769; i++)
+ {
+ if (hash[i] != NULL)
+ {
+ png_dsortp p = hash[i];
+ while (p)
+ {
+ t = p->next;
+ png_free(png_ptr, p);
+ p = t;
+ }
+ }
+ hash[i] = 0;
+ }
+ max_d += 96;
+ }
+ png_free(png_ptr, hash);
+ png_free(png_ptr, png_ptr->palette_to_index);
+ png_free(png_ptr, png_ptr->index_to_palette);
+ png_ptr->palette_to_index = NULL;
+ png_ptr->index_to_palette = NULL;
+ }
+ num_palette = maximum_colors;
+ }
+ if (png_ptr->palette == NULL)
+ {
+ png_ptr->palette = palette;
+ }
+ png_ptr->num_palette = (png_uint_16)num_palette;
+
+ if (full_quantize)
+ {
+ int i;
+ png_bytep distance;
+ int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS +
+ PNG_QUANTIZE_BLUE_BITS;
+ int num_red = (1 << PNG_QUANTIZE_RED_BITS);
+ int num_green = (1 << PNG_QUANTIZE_GREEN_BITS);
+ int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS);
+ png_size_t num_entries = ((png_size_t)1 << total_bits);
+
+ png_ptr->palette_lookup = (png_bytep )png_calloc(png_ptr,
+ (png_uint_32)(num_entries * png_sizeof(png_byte)));
+
+ distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
+ png_sizeof(png_byte)));
+ png_memset(distance, 0xff, num_entries * png_sizeof(png_byte));
+
+ for (i = 0; i < num_palette; i++)
+ {
+ int ir, ig, ib;
+ int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS));
+ int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS));
+ int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS));
+
+ for (ir = 0; ir < num_red; ir++)
+ {
+ /* int dr = abs(ir - r); */
+ int dr = ((ir > r) ? ir - r : r - ir);
+ int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS +
+ PNG_QUANTIZE_GREEN_BITS));
+
+ for (ig = 0; ig < num_green; ig++)
+ {
+ /* int dg = abs(ig - g); */
+ int dg = ((ig > g) ? ig - g : g - ig);
+ int dt = dr + dg;
+ int dm = ((dr > dg) ? dr : dg);
+ int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS);
+
+ for (ib = 0; ib < num_blue; ib++)
+ {
+ int d_index = index_g | ib;
+ /* int db = abs(ib - b); */
+ int db = ((ib > b) ? ib - b : b - ib);
+ int dmax = ((dm > db) ? dm : db);
+ int d = dmax + dt + db;
+
+ if (d < (int)distance[d_index])
+ {
+ distance[d_index] = (png_byte)d;
+ png_ptr->palette_lookup[d_index] = (png_byte)i;
+ }
+ }
+ }
+ }
+ }
+
+ png_free(png_ptr, distance);
+ }
+}
+#endif /* PNG_READ_QUANTIZE_SUPPORTED */
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
+/* Transform the image from the file_gamma to the screen_gamma. We
+ * only do transformations on images where the file_gamma and screen_gamma
+ * are not close reciprocals, otherwise it slows things down slightly, and
+ * also needlessly introduces small errors.
+ *
+ * We will turn off gamma transformation later if no semitransparent entries
+ * are present in the tRNS array for palette images. We can't do it here
+ * because we don't necessarily have the tRNS chunk yet.
+ */
+void PNGAPI
+png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
+{
+ png_debug(1, "in png_set_gamma");
+
+ if (png_ptr == NULL)
+ return;
+
+ if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) ||
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) ||
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
+ png_ptr->transformations |= PNG_GAMMA;
+ png_ptr->gamma = (float)file_gamma;
+ png_ptr->screen_gamma = (float)scrn_gamma;
+}
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expand paletted images to RGB, expand grayscale images of
+ * less than 8-bit depth to 8-bit depth, and expand tRNS chunks
+ * to alpha channels.
+ */
+void PNGAPI
+png_set_expand(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_expand");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+
+/* GRR 19990627: the following three functions currently are identical
+ * to png_set_expand(). However, it is entirely reasonable that someone
+ * might wish to expand an indexed image to RGB but *not* expand a single,
+ * fully transparent palette entry to a full alpha channel--perhaps instead
+ * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
+ * the transparent color with a particular RGB value, or drop tRNS entirely.
+ * IOW, a future version of the library may make the transformations flag
+ * a bit more fine-grained, with separate bits for each of these three
+ * functions.
+ *
+ * More to the point, these functions make it obvious what libpng will be
+ * doing, whereas "expand" can (and does) mean any number of things.
+ *
+ * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified
+ * to expand only the sample depth but not to expand the tRNS to alpha
+ * and its name was changed to png_set_expand_gray_1_2_4_to_8().
+ */
+
+/* Expand paletted images to RGB. */
+void PNGAPI
+png_set_palette_to_rgb(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_palette_to_rgb");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+
+/* Expand grayscale images of less than 8-bit depth to 8 bits. */
+void PNGAPI
+png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_EXPAND;
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+
+
+
+/* Expand tRNS chunks to alpha channels. */
+void PNGAPI
+png_set_tRNS_to_alpha(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_tRNS_to_alpha");
+
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+void PNGAPI
+png_set_gray_to_rgb(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_gray_to_rgb");
+
+ png_ptr->transformations |= PNG_GRAY_TO_RGB;
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+/* Convert a RGB image to a grayscale of the same width. This allows us,
+ * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
+ */
+
+void PNGAPI
+png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
+ double green)
+{
+ int red_fixed = (int)((float)red*100000.0 + 0.5);
+ int green_fixed = (int)((float)green*100000.0 + 0.5);
+ if (png_ptr == NULL)
+ return;
+ png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
+}
+#endif
+
+void PNGAPI
+png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
+ png_fixed_point red, png_fixed_point green)
+{
+ png_debug(1, "in png_set_rgb_to_gray");
+
+ if (png_ptr == NULL)
+ return;
+
+ switch(error_action)
+ {
+ case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY;
+ break;
+
+ case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
+ break;
+
+ case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
+ }
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ png_ptr->transformations |= PNG_EXPAND;
+#else
+ {
+ png_warning(png_ptr,
+ "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED");
+ png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
+ }
+#endif
+ {
+ png_uint_16 red_int, green_int;
+ if (red < 0 || green < 0)
+ {
+ red_int = 6968; /* .212671 * 32768 + .5 */
+ green_int = 23434; /* .715160 * 32768 + .5 */
+ }
+ else if (red + green < 100000L)
+ {
+ red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
+ green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
+ }
+ else
+ {
+ png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
+ red_int = 6968;
+ green_int = 23434;
+ }
+ png_ptr->rgb_to_gray_red_coeff = red_int;
+ png_ptr->rgb_to_gray_green_coeff = green_int;
+ png_ptr->rgb_to_gray_blue_coeff =
+ (png_uint_16)(32768 - red_int - green_int);
+ }
+}
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+void PNGAPI
+png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
+ read_user_transform_fn)
+{
+ png_debug(1, "in png_set_read_user_transform_fn");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ png_ptr->transformations |= PNG_USER_TRANSFORM;
+ png_ptr->read_user_transform_fn = read_user_transform_fn;
+#endif
+}
+#endif
+
+/* Initialize everything needed for the read. This includes modifying
+ * the palette.
+ */
+void /* PRIVATE */
+png_init_read_transformations(png_structp png_ptr)
+{
+ png_debug(1, "in png_init_read_transformations");
+
+ {
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_SHIFT_SUPPORTED) || \
+ defined(PNG_READ_GAMMA_SUPPORTED)
+ int color_type = png_ptr->color_type;
+#endif
+
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* Detect gray background and attempt to enable optimization
+ * for gray --> RGB case
+ *
+ * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
+ * RGB_ALPHA (in which case need_expand is superfluous anyway), the
+ * background color might actually be gray yet not be flagged as such.
+ * This is not a problem for the current code, which uses
+ * PNG_BACKGROUND_IS_GRAY only to decide when to do the
+ * png_do_gray_to_rgb() transformation.
+ */
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+ !(color_type & PNG_COLOR_MASK_COLOR))
+ {
+ png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+ } else if ((png_ptr->transformations & PNG_BACKGROUND) &&
+ !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+ (png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+ png_ptr->background.red == png_ptr->background.green &&
+ png_ptr->background.red == png_ptr->background.blue)
+ {
+ png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+ png_ptr->background.gray = png_ptr->background.red;
+ }
+#endif
+
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+ (png_ptr->transformations & PNG_EXPAND))
+ {
+ if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */
+ {
+ /* Expand background and tRNS chunks */
+ switch (png_ptr->bit_depth)
+ {
+ case 1:
+ png_ptr->background.gray *= (png_uint_16)0xff;
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+ {
+ png_ptr->trans_color.gray *= (png_uint_16)0xff;
+ png_ptr->trans_color.red = png_ptr->trans_color.green
+ = png_ptr->trans_color.blue = png_ptr->trans_color.gray;
+ }
+ break;
+
+ case 2:
+ png_ptr->background.gray *= (png_uint_16)0x55;
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+ {
+ png_ptr->trans_color.gray *= (png_uint_16)0x55;
+ png_ptr->trans_color.red = png_ptr->trans_color.green
+ = png_ptr->trans_color.blue = png_ptr->trans_color.gray;
+ }
+ break;
+
+ case 4:
+ png_ptr->background.gray *= (png_uint_16)0x11;
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+ {
+ png_ptr->trans_color.gray *= (png_uint_16)0x11;
+ png_ptr->trans_color.red = png_ptr->trans_color.green
+ = png_ptr->trans_color.blue = png_ptr->trans_color.gray;
+ }
+ break;
+
+ case 8:
+
+ case 16:
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ break;
+ }
+ }
+ else if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_ptr->background.red =
+ png_ptr->palette[png_ptr->background.index].red;
+ png_ptr->background.green =
+ png_ptr->palette[png_ptr->background.index].green;
+ png_ptr->background.blue =
+ png_ptr->palette[png_ptr->background.index].blue;
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+ if (png_ptr->transformations & PNG_INVERT_ALPHA)
+ {
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+#endif
+ {
+ /* Invert the alpha channel (in tRNS) unless the pixels are
+ * going to be expanded, in which case leave it for later
+ */
+ int i, istop;
+ istop=(int)png_ptr->num_trans;
+ for (i=0; i<istop; i++)
+ png_ptr->trans_alpha[i] = (png_byte)(255 - png_ptr->trans_alpha[i]);
+ }
+ }
+#endif
+
+ }
+ }
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
+ png_ptr->background_1 = png_ptr->background;
+#endif
+#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
+
+ if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0)
+ && (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0)
+ < PNG_GAMMA_THRESHOLD))
+ {
+ int i, k;
+ k=0;
+ for (i=0; i<png_ptr->num_trans; i++)
+ {
+ if (png_ptr->trans_alpha[i] != 0 && png_ptr->trans_alpha[i] != 0xff)
+ k=1; /* Partial transparency is present */
+ }
+ if (k == 0)
+ png_ptr->transformations &= ~PNG_GAMMA;
+ }
+
+ if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) &&
+ png_ptr->gamma != 0.0)
+ {
+ png_build_gamma_table(png_ptr, png_ptr->bit_depth);
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ if (png_ptr->transformations & PNG_BACKGROUND)
+ {
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ /* Could skip if no transparency */
+ png_color back, back_1;
+ png_colorp palette = png_ptr->palette;
+ int num_palette = png_ptr->num_palette;
+ int i;
+ if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
+ {
+ back.red = png_ptr->gamma_table[png_ptr->background.red];
+ back.green = png_ptr->gamma_table[png_ptr->background.green];
+ back.blue = png_ptr->gamma_table[png_ptr->background.blue];
+
+ back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
+ back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
+ back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
+ }
+ else
+ {
+ double g, gs;
+
+ switch (png_ptr->background_gamma_type)
+ {
+ case PNG_BACKGROUND_GAMMA_SCREEN:
+ g = (png_ptr->screen_gamma);
+ gs = 1.0;
+ break;
+
+ case PNG_BACKGROUND_GAMMA_FILE:
+ g = 1.0 / (png_ptr->gamma);
+ gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+ break;
+
+ case PNG_BACKGROUND_GAMMA_UNIQUE:
+ g = 1.0 / (png_ptr->background_gamma);
+ gs = 1.0 / (png_ptr->background_gamma *
+ png_ptr->screen_gamma);
+ break;
+ default:
+ g = 1.0; /* back_1 */
+ gs = 1.0; /* back */
+ }
+
+ if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD)
+ {
+ back.red = (png_byte)png_ptr->background.red;
+ back.green = (png_byte)png_ptr->background.green;
+ back.blue = (png_byte)png_ptr->background.blue;
+ }
+ else
+ {
+ back.red = (png_byte)(pow(
+ (double)png_ptr->background.red/255.0, gs) * 255.0 + .5);
+ back.green = (png_byte)(pow(
+ (double)png_ptr->background.green/255.0, gs) * 255.0
+ + .5);
+ back.blue = (png_byte)(pow(
+ (double)png_ptr->background.blue/255.0, gs) * 255.0 + .5);
+ }
+
+ back_1.red = (png_byte)(pow(
+ (double)png_ptr->background.red/255.0, g) * 255.0 + .5);
+ back_1.green = (png_byte)(pow(
+ (double)png_ptr->background.green/255.0, g) * 255.0 + .5);
+ back_1.blue = (png_byte)(pow(
+ (double)png_ptr->background.blue/255.0, g) * 255.0 + .5);
+ }
+ for (i = 0; i < num_palette; i++)
+ {
+ if (i < (int)png_ptr->num_trans && png_ptr->trans_alpha[i] != 0xff)
+ {
+ if (png_ptr->trans_alpha[i] == 0)
+ {
+ palette[i] = back;
+ }
+ else /* if (png_ptr->trans_alpha[i] != 0xff) */
+ {
+ png_byte v, w;
+
+ v = png_ptr->gamma_to_1[palette[i].red];
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.red);
+ palette[i].red = png_ptr->gamma_from_1[w];
+
+ v = png_ptr->gamma_to_1[palette[i].green];
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.green);
+ palette[i].green = png_ptr->gamma_from_1[w];
+
+ v = png_ptr->gamma_to_1[palette[i].blue];
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue);
+ palette[i].blue = png_ptr->gamma_from_1[w];
+ }
+ }
+ else
+ {
+ palette[i].red = png_ptr->gamma_table[palette[i].red];
+ palette[i].green = png_ptr->gamma_table[palette[i].green];
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+ }
+ }
+ /* Prevent the transformations being done again, and make sure
+ * that the now spurious alpha channel is stripped - the code
+ * has just reduced background composition and gamma correction
+ * to a simple alpha channel strip.
+ */
+ png_ptr->transformations &= ~PNG_BACKGROUND;
+ png_ptr->transformations &= ~PNG_GAMMA;
+ png_ptr->transformations |= PNG_STRIP_ALPHA;
+ }
+ /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
+ else
+ /* color_type != PNG_COLOR_TYPE_PALETTE */
+ {
+ double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1);
+ double g = 1.0;
+ double gs = 1.0;
+
+ switch (png_ptr->background_gamma_type)
+ {
+ case PNG_BACKGROUND_GAMMA_SCREEN:
+ g = (png_ptr->screen_gamma);
+ gs = 1.0;
+ break;
+
+ case PNG_BACKGROUND_GAMMA_FILE:
+ g = 1.0 / (png_ptr->gamma);
+ gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+ break;
+
+ case PNG_BACKGROUND_GAMMA_UNIQUE:
+ g = 1.0 / (png_ptr->background_gamma);
+ gs = 1.0 / (png_ptr->background_gamma *
+ png_ptr->screen_gamma);
+ break;
+ }
+
+ png_ptr->background_1.gray = (png_uint_16)(pow(
+ (double)png_ptr->background.gray / m, g) * m + .5);
+ png_ptr->background.gray = (png_uint_16)(pow(
+ (double)png_ptr->background.gray / m, gs) * m + .5);
+
+ if ((png_ptr->background.red != png_ptr->background.green) ||
+ (png_ptr->background.red != png_ptr->background.blue) ||
+ (png_ptr->background.red != png_ptr->background.gray))
+ {
+ /* RGB or RGBA with color background */
+ png_ptr->background_1.red = (png_uint_16)(pow(
+ (double)png_ptr->background.red / m, g) * m + .5);
+ png_ptr->background_1.green = (png_uint_16)(pow(
+ (double)png_ptr->background.green / m, g) * m + .5);
+ png_ptr->background_1.blue = (png_uint_16)(pow(
+ (double)png_ptr->background.blue / m, g) * m + .5);
+ png_ptr->background.red = (png_uint_16)(pow(
+ (double)png_ptr->background.red / m, gs) * m + .5);
+ png_ptr->background.green = (png_uint_16)(pow(
+ (double)png_ptr->background.green / m, gs) * m + .5);
+ png_ptr->background.blue = (png_uint_16)(pow(
+ (double)png_ptr->background.blue / m, gs) * m + .5);
+ }
+ else
+ {
+ /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
+ png_ptr->background_1.red = png_ptr->background_1.green
+ = png_ptr->background_1.blue = png_ptr->background_1.gray;
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ }
+ }
+ }
+ else
+ /* Transformation does not include PNG_BACKGROUND */
+#endif /* PNG_READ_BACKGROUND_SUPPORTED */
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_colorp palette = png_ptr->palette;
+ int num_palette = png_ptr->num_palette;
+ int i;
+
+ for (i = 0; i < num_palette; i++)
+ {
+ palette[i].red = png_ptr->gamma_table[palette[i].red];
+ palette[i].green = png_ptr->gamma_table[palette[i].green];
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+ }
+
+ /* Done the gamma correction. */
+ png_ptr->transformations &= ~PNG_GAMMA;
+ }
+ }
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ else
+#endif
+#endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ /* No GAMMA transformation */
+ if ((png_ptr->transformations & PNG_BACKGROUND) &&
+ (color_type == PNG_COLOR_TYPE_PALETTE))
+ {
+ int i;
+ int istop = (int)png_ptr->num_trans;
+ png_color back;
+ png_colorp palette = png_ptr->palette;
+
+ back.red = (png_byte)png_ptr->background.red;
+ back.green = (png_byte)png_ptr->background.green;
+ back.blue = (png_byte)png_ptr->background.blue;
+
+ for (i = 0; i < istop; i++)
+ {
+ if (png_ptr->trans_alpha[i] == 0)
+ {
+ palette[i] = back;
+ }
+ else if (png_ptr->trans_alpha[i] != 0xff)
+ {
+ /* The png_composite() macro is defined in png.h */
+ png_composite(palette[i].red, palette[i].red,
+ png_ptr->trans_alpha[i], back.red);
+ png_composite(palette[i].green, palette[i].green,
+ png_ptr->trans_alpha[i], back.green);
+ png_composite(palette[i].blue, palette[i].blue,
+ png_ptr->trans_alpha[i], back.blue);
+ }
+ }
+
+ /* Handled alpha, still need to strip the channel. */
+ png_ptr->transformations &= ~PNG_BACKGROUND;
+ png_ptr->transformations |= PNG_STRIP_ALPHA;
+ }
+#endif /* PNG_READ_BACKGROUND_SUPPORTED */
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+ if ((png_ptr->transformations & PNG_SHIFT) &&
+ (color_type == PNG_COLOR_TYPE_PALETTE))
+ {
+ png_uint_16 i;
+ png_uint_16 istop = png_ptr->num_palette;
+ int sr = 8 - png_ptr->sig_bit.red;
+ int sg = 8 - png_ptr->sig_bit.green;
+ int sb = 8 - png_ptr->sig_bit.blue;
+
+ if (sr < 0 || sr > 8)
+ sr = 0;
+ if (sg < 0 || sg > 8)
+ sg = 0;
+ if (sb < 0 || sb > 8)
+ sb = 0;
+ for (i = 0; i < istop; i++)
+ {
+ png_ptr->palette[i].red >>= sr;
+ png_ptr->palette[i].green >>= sg;
+ png_ptr->palette[i].blue >>= sb;
+ }
+ }
+#endif /* PNG_READ_SHIFT_SUPPORTED */
+ }
+#if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \
+ && !defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr)
+ return;
+#endif
+}
+
+/* Modify the info structure to reflect the transformations. The
+ * info should be updated so a PNG file could be written with it,
+ * assuming the transformations result in valid PNG data.
+ */
+void /* PRIVATE */
+png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
+{
+ png_debug(1, "in png_read_transform_info");
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ if (png_ptr->transformations & PNG_EXPAND)
+ {
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (png_ptr->num_trans &&
+ (png_ptr->transformations & PNG_EXPAND_tRNS))
+ info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+ else
+ info_ptr->color_type = PNG_COLOR_TYPE_RGB;
+ info_ptr->bit_depth = 8;
+ info_ptr->num_trans = 0;
+ }
+ else
+ {
+ if (png_ptr->num_trans)
+ {
+ if (png_ptr->transformations & PNG_EXPAND_tRNS)
+ info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+ }
+ if (info_ptr->bit_depth < 8)
+ info_ptr->bit_depth = 8;
+ info_ptr->num_trans = 0;
+ }
+ }
+#endif
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ if (png_ptr->transformations & PNG_BACKGROUND)
+ {
+ info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
+ info_ptr->num_trans = 0;
+ info_ptr->background = png_ptr->background;
+ }
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (png_ptr->transformations & PNG_GAMMA)
+ {
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ info_ptr->gamma = png_ptr->gamma;
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ info_ptr->int_gamma = png_ptr->int_gamma;
+#endif
+ }
+#endif
+
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+ if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16))
+ info_ptr->bit_depth = 8;
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ if (png_ptr->transformations & PNG_GRAY_TO_RGB)
+ info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+ info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR;
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ if (png_ptr->transformations & PNG_QUANTIZE)
+ {
+ if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
+ (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
+ png_ptr->palette_lookup && info_ptr->bit_depth == 8)
+ {
+ info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
+ }
+ }
+#endif
+
+#ifdef PNG_READ_PACK_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))
+ info_ptr->bit_depth = 8;
+#endif
+
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ info_ptr->channels = 1;
+ else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
+ info_ptr->channels = 3;
+ else
+ info_ptr->channels = 1;
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
+ info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
+#endif
+
+ if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
+ info_ptr->channels++;
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+ /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
+ if ((png_ptr->transformations & PNG_FILLER) &&
+ ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
+ (info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))
+ {
+ info_ptr->channels++;
+ /* If adding a true alpha channel not just filler */
+ if (png_ptr->transformations & PNG_ADD_ALPHA)
+ info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+ }
+#endif
+
+#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
+defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+ if (png_ptr->transformations & PNG_USER_TRANSFORM)
+ {
+ if (info_ptr->bit_depth < png_ptr->user_transform_depth)
+ info_ptr->bit_depth = png_ptr->user_transform_depth;
+ if (info_ptr->channels < png_ptr->user_transform_channels)
+ info_ptr->channels = png_ptr->user_transform_channels;
+ }
+#endif
+
+ info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
+ info_ptr->bit_depth);
+
+ info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
+
+#ifndef PNG_READ_EXPAND_SUPPORTED
+ if (png_ptr)
+ return;
+#endif
+}
+
+/* Transform the row. The order of transformations is significant,
+ * and is very touchy. If you add a transformation, take care to
+ * decide how it fits in with the other transformations here.
+ */
+void /* PRIVATE */
+png_do_read_transformations(png_structp png_ptr)
+{
+ png_debug(1, "in png_do_read_transformations");
+
+ if (png_ptr->row_buf == NULL)
+ {
+#ifdef PNG_STDIO_SUPPORTED
+ char msg[50];
+
+ png_snprintf2(msg, 50,
+ "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number,
+ png_ptr->pass);
+ png_error(png_ptr, msg);
+#else
+ png_error(png_ptr, "NULL row buffer");
+#endif
+ }
+#ifdef PNG_WARN_UNINITIALIZED_ROW
+ if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
+ /* Application has failed to call either png_read_start_image()
+ * or png_read_update_info() after setting transforms that expand
+ * pixels. This check added to libpng-1.2.19
+ */
+#if (PNG_WARN_UNINITIALIZED_ROW==1)
+ png_error(png_ptr, "Uninitialized row");
+#else
+ png_warning(png_ptr, "Uninitialized row");
+#endif
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ if (png_ptr->transformations & PNG_EXPAND)
+ {
+ if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
+ }
+ else
+ {
+ if (png_ptr->num_trans &&
+ (png_ptr->transformations & PNG_EXPAND_tRNS))
+ png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ &(png_ptr->trans_color));
+ else
+ png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ NULL);
+ }
+ }
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
+ png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA));
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+ {
+ int rgb_error =
+ png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info),
+ png_ptr->row_buf + 1);
+ if (rgb_error)
+ {
+ png_ptr->rgb_to_gray_status=1;
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+ PNG_RGB_TO_GRAY_WARN)
+ png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+ PNG_RGB_TO_GRAY_ERR)
+ png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+ }
+ }
+#endif
+
+/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
+ *
+ * In most cases, the "simple transparency" should be done prior to doing
+ * gray-to-RGB, or you will have to test 3x as many bytes to check if a
+ * pixel is transparent. You would also need to make sure that the
+ * transparency information is upgraded to RGB.
+ *
+ * To summarize, the current flow is:
+ * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
+ * with background "in place" if transparent,
+ * convert to RGB if necessary
+ * - Gray + alpha -> composite with gray background and remove alpha bytes,
+ * convert to RGB if necessary
+ *
+ * To support RGB backgrounds for gray images we need:
+ * - Gray + simple transparency -> convert to RGB + simple transparency,
+ * compare 3 or 6 bytes and composite with
+ * background "in place" if transparent
+ * (3x compare/pixel compared to doing
+ * composite with gray bkgrnd)
+ * - Gray + alpha -> convert to RGB + alpha, composite with background and
+ * remove alpha bytes (3x float
+ * operations/pixel compared with composite
+ * on gray background)
+ *
+ * Greg's change will do this. The reason it wasn't done before is for
+ * performance, as this increases the per-pixel operations. If we would check
+ * in advance if the background was gray or RGB, and position the gray-to-RGB
+ * transform appropriately, then it would save a lot of work/time.
+ */
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* If gray -> RGB, do so now only if background is non-gray; else do later
+ * for performance reasons
+ */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+ !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
+ png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ if ((png_ptr->transformations & PNG_BACKGROUND) &&
+ ((png_ptr->num_trans != 0 ) ||
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA)))
+ png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ &(png_ptr->trans_color), &(png_ptr->background)
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ , &(png_ptr->background_1),
+ png_ptr->gamma_table, png_ptr->gamma_from_1,
+ png_ptr->gamma_to_1, png_ptr->gamma_16_table,
+ png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1,
+ png_ptr->gamma_shift
+#endif
+);
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if ((png_ptr->transformations & PNG_GAMMA) &&
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ !((png_ptr->transformations & PNG_BACKGROUND) &&
+ ((png_ptr->num_trans != 0) ||
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
+#endif
+ (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
+ png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ png_ptr->gamma_table, png_ptr->gamma_16_table,
+ png_ptr->gamma_shift);
+#endif
+
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+ if (png_ptr->transformations & PNG_16_TO_8)
+ png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ if (png_ptr->transformations & PNG_QUANTIZE)
+ {
+ png_do_quantize((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,
+ png_ptr->palette_lookup, png_ptr->quantize_index);
+ if (png_ptr->row_info.rowbytes == (png_uint_32)0)
+ png_error(png_ptr, "png_do_quantize returned rowbytes=0");
+ }
+#endif
+
+#ifdef PNG_READ_INVERT_SUPPORTED
+ if (png_ptr->transformations & PNG_INVERT_MONO)
+ png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+ if (png_ptr->transformations & PNG_SHIFT)
+ png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ &(png_ptr->shift));
+#endif
+
+#ifdef PNG_READ_PACK_SUPPORTED
+ if (png_ptr->transformations & PNG_PACK)
+ png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_BGR_SUPPORTED
+ if (png_ptr->transformations & PNG_BGR)
+ png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* If gray -> RGB, do so now only if we did not do so above */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+ (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
+ png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+ if (png_ptr->transformations & PNG_FILLER)
+ png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ (png_uint_32)png_ptr->filler, png_ptr->flags);
+#endif
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+ if (png_ptr->transformations & PNG_INVERT_ALPHA)
+ png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+ if (png_ptr->transformations & PNG_SWAP_ALPHA)
+ png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_SWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_SWAP_BYTES)
+ png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ if (png_ptr->transformations & PNG_USER_TRANSFORM)
+ {
+ if (png_ptr->read_user_transform_fn != NULL)
+ (*(png_ptr->read_user_transform_fn)) /* User read transform function */
+ (png_ptr, /* png_ptr */
+ &(png_ptr->row_info), /* row_info: */
+ /* png_uint_32 width; width of row */
+ /* png_uint_32 rowbytes; number of bytes in row */
+ /* png_byte color_type; color type of pixels */
+ /* png_byte bit_depth; bit depth of samples */
+ /* png_byte channels; number of channels (1-4) */
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */
+ png_ptr->row_buf + 1); /* start of pixel data for row */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+ if (png_ptr->user_transform_depth)
+ png_ptr->row_info.bit_depth = png_ptr->user_transform_depth;
+ if (png_ptr->user_transform_channels)
+ png_ptr->row_info.channels = png_ptr->user_transform_channels;
+#endif
+ png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
+ png_ptr->row_info.channels);
+ png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
+ png_ptr->row_info.width);
+ }
+#endif
+
+}
+
+#ifdef PNG_READ_PACK_SUPPORTED
+/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
+ * without changing the actual values. Thus, if you had a row with
+ * a bit depth of 1, you would end up with bytes that only contained
+ * the numbers 0 or 1. If you would rather they contain 0 and 255, use
+ * png_do_shift() after this.
+ */
+void /* PRIVATE */
+png_do_unpack(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_unpack");
+
+ if (row_info->bit_depth < 8)
+ {
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
+ png_bytep dp = row + (png_size_t)row_width - 1;
+ png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x01);
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
+ png_bytep dp = row + (png_size_t)row_width - 1;
+ png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x03);
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
+ png_bytep dp = row + (png_size_t)row_width - 1;
+ png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x0f);
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift = 4;
+
+ dp--;
+ }
+ break;
+ }
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+ row_info->rowbytes = row_width * row_info->channels;
+ }
+}
+#endif
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+/* Reverse the effects of png_do_shift. This routine merely shifts the
+ * pixels back to their significant bits values. Thus, if you have
+ * a row of bit depth 8, but only 5 are significant, this will shift
+ * the values back to 0 through 31.
+ */
+void /* PRIVATE */
+png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
+{
+ png_debug(1, "in png_do_unshift");
+
+ if (
+ row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ int shift[4];
+ int channels = 0;
+ int c;
+ png_uint_16 value = 0;
+ png_uint_32 row_width = row_info->width;
+
+ if (row_info->color_type & PNG_COLOR_MASK_COLOR)
+ {
+ shift[channels++] = row_info->bit_depth - sig_bits->red;
+ shift[channels++] = row_info->bit_depth - sig_bits->green;
+ shift[channels++] = row_info->bit_depth - sig_bits->blue;
+ }
+ else
+ {
+ shift[channels++] = row_info->bit_depth - sig_bits->gray;
+ }
+ if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
+ {
+ shift[channels++] = row_info->bit_depth - sig_bits->alpha;
+ }
+
+ for (c = 0; c < channels; c++)
+ {
+ if (shift[c] <= 0)
+ shift[c] = 0;
+ else
+ value = 1;
+ }
+
+ if (!value)
+ return;
+
+ switch (row_info->bit_depth)
+ {
+ case 2:
+ {
+ png_bytep bp;
+ png_uint_32 i;
+ png_uint_32 istop = row_info->rowbytes;
+
+ for (bp = row, i = 0; i < istop; i++)
+ {
+ *bp >>= 1;
+ *bp++ &= 0x55;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep bp = row;
+ png_uint_32 i;
+ png_uint_32 istop = row_info->rowbytes;
+ png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) |
+ (png_byte)((int)0xf >> shift[0]));
+
+ for (i = 0; i < istop; i++)
+ {
+ *bp >>= shift[0];
+ *bp++ &= mask;
+ }
+ break;
+ }
+
+ case 8:
+ {
+ png_bytep bp = row;
+ png_uint_32 i;
+ png_uint_32 istop = row_width * channels;
+
+ for (i = 0; i < istop; i++)
+ {
+ *bp++ >>= shift[i%channels];
+ }
+ break;
+ }
+
+ case 16:
+ {
+ png_bytep bp = row;
+ png_uint_32 i;
+ png_uint_32 istop = channels * row_width;
+
+ for (i = 0; i < istop; i++)
+ {
+ value = (png_uint_16)((*bp << 8) + *(bp + 1));
+ value >>= shift[i%channels];
+ *bp++ = (png_byte)(value >> 8);
+ *bp++ = (png_byte)(value & 0xff);
+ }
+ break;
+ }
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+/* Chop rows of bit depth 16 down to 8 */
+void /* PRIVATE */
+png_do_chop(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_chop");
+
+ if (row_info->bit_depth == 16)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ png_uint_32 i;
+ png_uint_32 istop = row_info->width * row_info->channels;
+
+ for (i = 0; i<istop; i++, sp += 2, dp++)
+ {
+#ifdef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+ /* This does a more accurate scaling of the 16-bit color
+ * value, rather than a simple low-byte truncation.
+ *
+ * What the ideal calculation should be:
+ * *dp = (((((png_uint_32)(*sp) << 8) |
+ * (png_uint_32)(*(sp + 1))) * 255 + 127)
+ * / (png_uint_32)65535L;
+ *
+ * GRR: no, I think this is what it really should be:
+ * *dp = (((((png_uint_32)(*sp) << 8) |
+ * (png_uint_32)(*(sp + 1))) + 128L)
+ * / (png_uint_32)257L;
+ *
+ * GRR: here's the exact calculation with shifts:
+ * temp = (((png_uint_32)(*sp) << 8) |
+ * (png_uint_32)(*(sp + 1))) + 128L;
+ * *dp = (temp - (temp >> 8)) >> 8;
+ *
+ * Approximate calculation with shift/add instead of multiply/divide:
+ * *dp = ((((png_uint_32)(*sp) << 8) |
+ * (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8;
+ *
+ * What we actually do to avoid extra shifting and conversion:
+ */
+
+ *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0);
+#else
+ /* Simply discard the low order byte */
+ *dp = *sp;
+#endif
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+ row_info->rowbytes = row_info->width * row_info->channels;
+ }
+}
+#endif
+
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+void /* PRIVATE */
+png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_read_swap_alpha");
+
+ {
+ png_uint_32 row_width = row_info->width;
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ /* This converts from RGBA to ARGB */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save;
+ }
+ }
+ /* This converts from RRGGBBAA to AARRGGBB */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save[2];
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save[0] = *(--sp);
+ save[1] = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save[0];
+ *(--dp) = save[1];
+ }
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ /* This converts from GA to AG */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save;
+ }
+ }
+ /* This converts from GGAA to AAGG */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save[2];
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save[0] = *(--sp);
+ save[1] = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save[0];
+ *(--dp) = save[1];
+ }
+ }
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+void /* PRIVATE */
+png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_read_invert_alpha");
+
+ {
+ png_uint_32 row_width = row_info->width;
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ /* This inverts the alpha channel in RGBA */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+
+/* This does nothing:
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ We can replace it with:
+*/
+ sp-=3;
+ dp=sp;
+ }
+ }
+ /* This inverts the alpha channel in RRGGBBAA */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = (png_byte)(255 - *(--sp));
+
+/* This does nothing:
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ We can replace it with:
+*/
+ sp-=6;
+ dp=sp;
+ }
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ /* This inverts the alpha channel in GA */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = *(--sp);
+ }
+ }
+ /* This inverts the alpha channel in GGAA */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = (png_byte)(255 - *(--sp));
+/*
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+*/
+ sp-=2;
+ dp=sp;
+ }
+ }
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+/* Add filler channel if we have RGB color */
+void /* PRIVATE */
+png_do_read_filler(png_row_infop row_info, png_bytep row,
+ png_uint_32 filler, png_uint_32 flags)
+{
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ png_byte hi_filler = (png_byte)((filler>>8) & 0xff);
+ png_byte lo_filler = (png_byte)(filler & 0xff);
+
+ png_debug(1, "in png_do_read_filler");
+
+ if (
+ row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This changes the data from G to GX */
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ png_bytep sp = row + (png_size_t)row_width;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ row_info->channels = 2;
+ row_info->pixel_depth = 16;
+ row_info->rowbytes = row_width * 2;
+ }
+ /* This changes the data from G to XG */
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 2;
+ row_info->pixel_depth = 16;
+ row_info->rowbytes = row_width * 2;
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ /* This changes the data from GG to GGXX */
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ png_bytep sp = row + (png_size_t)row_width * 2;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ row_info->channels = 2;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ /* This changes the data from GG to XXGG */
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width * 2;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 2;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ }
+ } /* COLOR_TYPE == GRAY */
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This changes the data from RGB to RGBX */
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ png_bytep sp = row + (png_size_t)row_width * 3;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ row_info->channels = 4;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ /* This changes the data from RGB to XRGB */
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width * 3;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 4;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ /* This changes the data from RRGGBB to RRGGBBXX */
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ png_bytep sp = row + (png_size_t)row_width * 6;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ row_info->channels = 4;
+ row_info->pixel_depth = 64;
+ row_info->rowbytes = row_width * 8;
+ }
+ /* This changes the data from RRGGBB to XXRRGGBB */
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width * 6;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 4;
+ row_info->pixel_depth = 64;
+ row_info->rowbytes = row_width * 8;
+ }
+ }
+ } /* COLOR_TYPE == RGB */
+}
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+/* Expand grayscale files to RGB, with or without alpha */
+void /* PRIVATE */
+png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
+{
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ png_debug(1, "in png_do_gray_to_rgb");
+
+ if (row_info->bit_depth >= 8 &&
+ !(row_info->color_type & PNG_COLOR_MASK_COLOR))
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + (png_size_t)row_width - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *sp;
+ *(dp--) = *sp;
+ *(dp--) = *(sp--);
+ }
+ }
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width * 2 - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 4;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ }
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + (png_size_t)row_width * 2 - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *(sp--);
+ *(dp--) = *sp;
+ *(dp--) = *sp;
+ *(dp--) = *(sp--);
+ }
+ }
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width * 4 - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 4;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ }
+ }
+ }
+ row_info->channels += (png_byte)2;
+ row_info->color_type |= PNG_COLOR_MASK_COLOR;
+ row_info->pixel_depth = (png_byte)(row_info->channels *
+ row_info->bit_depth);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* Reduce RGB files to grayscale, with or without alpha
+ * using the equation given in Poynton's ColorFAQ at
+ * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008)
+ * New link:
+ * <http://www.poynton.com/notes/colour_and_gamma/>
+ * Charles Poynton poynton at poynton.com
+ *
+ * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+ *
+ * We approximate this with
+ *
+ * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B
+ *
+ * which can be expressed with integers as
+ *
+ * Y = (6969 * R + 23434 * G + 2365 * B)/32768
+ *
+ * The calculation is to be done in a linear colorspace.
+ *
+ * Other integer coefficents can be used via png_set_rgb_to_gray().
+ */
+int /* PRIVATE */
+png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
+
+{
+ png_uint_32 i;
+
+ png_uint_32 row_width = row_info->width;
+ int rgb_error = 0;
+
+ png_debug(1, "in png_do_rgb_to_gray");
+
+ if (
+ (row_info->color_type & PNG_COLOR_MASK_COLOR))
+ {
+ png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
+ png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
+ png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if (row_info->bit_depth == 8)
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = png_ptr->gamma_to_1[*(sp++)];
+ png_byte green = png_ptr->gamma_to_1[*(sp++)];
+ png_byte blue = png_ptr->gamma_to_1[*(sp++)];
+ if (red != green || red != blue)
+ {
+ rgb_error |= 1;
+ *(dp++) = png_ptr->gamma_from_1[
+ (rc*red + gc*green + bc*blue)>>15];
+ }
+ else
+ *(dp++) = *(sp - 1);
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = *(sp++);
+ png_byte green = *(sp++);
+ png_byte blue = *(sp++);
+ if (red != green || red != blue)
+ {
+ rgb_error |= 1;
+ *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
+ }
+ else
+ *(dp++) = *(sp - 1);
+ }
+ }
+ }
+
+ else /* RGB bit_depth == 16 */
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->gamma_16_to_1 != NULL &&
+ png_ptr->gamma_16_from_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, w;
+
+ red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+
+ if (red == green && red == blue)
+ w = red;
+ else
+ {
+ png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
+ png_ptr->gamma_shift][red>>8];
+ png_uint_16 green_1 =
+ png_ptr->gamma_16_to_1[(green&0xff) >>
+ png_ptr->gamma_shift][green>>8];
+ png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
+ png_ptr->gamma_shift][blue>>8];
+ png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1
+ + bc*blue_1)>>15);
+ w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
+ png_ptr->gamma_shift][gray16 >> 8];
+ rgb_error |= 1;
+ }
+
+ *(dp++) = (png_byte)((w>>8) & 0xff);
+ *(dp++) = (png_byte)(w & 0xff);
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, gray16;
+
+ red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+
+ if (red != green || red != blue)
+ rgb_error |= 1;
+ gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
+ *(dp++) = (png_byte)((gray16>>8) & 0xff);
+ *(dp++) = (png_byte)(gray16 & 0xff);
+ }
+ }
+ }
+ }
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = png_ptr->gamma_to_1[*(sp++)];
+ png_byte green = png_ptr->gamma_to_1[*(sp++)];
+ png_byte blue = png_ptr->gamma_to_1[*(sp++)];
+ if (red != green || red != blue)
+ rgb_error |= 1;
+ *(dp++) = png_ptr->gamma_from_1
+ [(rc*red + gc*green + bc*blue)>>15];
+ *(dp++) = *(sp++); /* alpha */
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = *(sp++);
+ png_byte green = *(sp++);
+ png_byte blue = *(sp++);
+ if (red != green || red != blue)
+ rgb_error |= 1;
+ *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
+ *(dp++) = *(sp++); /* alpha */
+ }
+ }
+ }
+ else /* RGBA bit_depth == 16 */
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->gamma_16_to_1 != NULL &&
+ png_ptr->gamma_16_from_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, w;
+
+ red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+
+ if (red == green && red == blue)
+ w = red;
+ else
+ {
+ png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
+ png_ptr->gamma_shift][red>>8];
+ png_uint_16 green_1 =
+ png_ptr->gamma_16_to_1[(green&0xff) >>
+ png_ptr->gamma_shift][green>>8];
+ png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
+ png_ptr->gamma_shift][blue>>8];
+ png_uint_16 gray16 = (png_uint_16)((rc * red_1
+ + gc * green_1 + bc * blue_1)>>15);
+ w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
+ png_ptr->gamma_shift][gray16 >> 8];
+ rgb_error |= 1;
+ }
+
+ *(dp++) = (png_byte)((w>>8) & 0xff);
+ *(dp++) = (png_byte)(w & 0xff);
+ *(dp++) = *(sp++); /* alpha */
+ *(dp++) = *(sp++);
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, gray16;
+ red = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
+ green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
+ blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
+ if (red != green || red != blue)
+ rgb_error |= 1;
+ gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
+ *(dp++) = (png_byte)((gray16>>8) & 0xff);
+ *(dp++) = (png_byte)(gray16 & 0xff);
+ *(dp++) = *(sp++); /* alpha */
+ *(dp++) = *(sp++);
+ }
+ }
+ }
+ }
+ row_info->channels -= (png_byte)2;
+ row_info->color_type &= ~PNG_COLOR_MASK_COLOR;
+ row_info->pixel_depth = (png_byte)(row_info->channels *
+ row_info->bit_depth);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+ return rgb_error;
+}
+#endif
+
+/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth
+ * large of png_color. This lets grayscale images be treated as
+ * paletted. Most useful for gamma correction and simplification
+ * of code.
+ */
+void PNGAPI
+png_build_grayscale_palette(int bit_depth, png_colorp palette)
+{
+ int num_palette;
+ int color_inc;
+ int i;
+ int v;
+
+ png_debug(1, "in png_do_build_grayscale_palette");
+
+ if (palette == NULL)
+ return;
+
+ switch (bit_depth)
+ {
+ case 1:
+ num_palette = 2;
+ color_inc = 0xff;
+ break;
+
+ case 2:
+ num_palette = 4;
+ color_inc = 0x55;
+ break;
+
+ case 4:
+ num_palette = 16;
+ color_inc = 0x11;
+ break;
+
+ case 8:
+ num_palette = 256;
+ color_inc = 1;
+ break;
+
+ default:
+ num_palette = 0;
+ color_inc = 0;
+ break;
+ }
+
+ for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
+ {
+ palette[i].red = (png_byte)v;
+ palette[i].green = (png_byte)v;
+ palette[i].blue = (png_byte)v;
+ }
+}
+
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+/* Replace any alpha or transparency with the supplied background color.
+ * "background" is already in the screen gamma, while "background_1" is
+ * at a gamma of 1.0. Paletted files have already been taken care of.
+ */
+void /* PRIVATE */
+png_do_background(png_row_infop row_info, png_bytep row,
+ png_color_16p trans_color, png_color_16p background
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ , png_color_16p background_1,
+ png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
+ png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
+ png_uint_16pp gamma_16_to_1, int gamma_shift
+#endif
+ )
+{
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+ int shift;
+
+ png_debug(1, "in png_do_background");
+
+ if (background != NULL &&
+ (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) ||
+ (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_color)))
+ {
+ switch (row_info->color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ sp = row;
+ shift = 7;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x01)
+ == trans_color->gray)
+ {
+ *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
+ *sp |= (png_byte)(background->gray << shift);
+ }
+ if (!shift)
+ {
+ shift = 7;
+ sp++;
+ }
+ else
+ shift--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ shift = 6;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x03)
+ == trans_color->gray)
+ {
+ *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+ *sp |= (png_byte)(background->gray << shift);
+ }
+ else
+ {
+ png_byte p = (png_byte)((*sp >> shift) & 0x03);
+ png_byte g = (png_byte)((gamma_table [p | (p << 2) |
+ (p << 4) | (p << 6)] >> 6) & 0x03);
+ *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+ *sp |= (png_byte)(g << shift);
+ }
+ if (!shift)
+ {
+ shift = 6;
+ sp++;
+ }
+ else
+ shift -= 2;
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ shift = 6;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x03)
+ == trans_color->gray)
+ {
+ *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+ *sp |= (png_byte)(background->gray << shift);
+ }
+ if (!shift)
+ {
+ shift = 6;
+ sp++;
+ }
+ else
+ shift -= 2;
+ }
+ }
+ break;
+ }
+
+ case 4:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ shift = 4;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x0f)
+ == trans_color->gray)
+ {
+ *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+ *sp |= (png_byte)(background->gray << shift);
+ }
+ else
+ {
+ png_byte p = (png_byte)((*sp >> shift) & 0x0f);
+ png_byte g = (png_byte)((gamma_table[p |
+ (p << 4)] >> 4) & 0x0f);
+ *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+ *sp |= (png_byte)(g << shift);
+ }
+ if (!shift)
+ {
+ shift = 4;
+ sp++;
+ }
+ else
+ shift -= 4;
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ shift = 4;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x0f)
+ == trans_color->gray)
+ {
+ *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+ *sp |= (png_byte)(background->gray << shift);
+ }
+ if (!shift)
+ {
+ shift = 4;
+ sp++;
+ }
+ else
+ shift -= 4;
+ }
+ }
+ break;
+ }
+
+ case 8:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ if (*sp == trans_color->gray)
+ {
+ *sp = (png_byte)background->gray;
+ }
+ else
+ {
+ *sp = gamma_table[*sp];
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ if (*sp == trans_color->gray)
+ {
+ *sp = (png_byte)background->gray;
+ }
+ }
+ }
+ break;
+ }
+
+ case 16:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_uint_16 v;
+
+ v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ if (v == trans_color->gray)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)((background->gray >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(background->gray & 0xff);
+ }
+ else
+ {
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_uint_16 v;
+
+ v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ if (v == trans_color->gray)
+ {
+ *sp = (png_byte)((background->gray >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(background->gray & 0xff);
+ }
+ }
+ }
+ break;
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_RGB:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 3)
+ {
+ if (*sp == trans_color->red &&
+ *(sp + 1) == trans_color->green &&
+ *(sp + 2) == trans_color->blue)
+ {
+ *sp = (png_byte)background->red;
+ *(sp + 1) = (png_byte)background->green;
+ *(sp + 2) = (png_byte)background->blue;
+ }
+ else
+ {
+ *sp = gamma_table[*sp];
+ *(sp + 1) = gamma_table[*(sp + 1)];
+ *(sp + 2) = gamma_table[*(sp + 2)];
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 3)
+ {
+ if (*sp == trans_color->red &&
+ *(sp + 1) == trans_color->green &&
+ *(sp + 2) == trans_color->blue)
+ {
+ *sp = (png_byte)background->red;
+ *(sp + 1) = (png_byte)background->green;
+ *(sp + 2) = (png_byte)background->blue;
+ }
+ }
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 6)
+ {
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
+ png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
+ if (r == trans_color->red && g == trans_color->green &&
+ b == trans_color->blue)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)((background->red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(background->red & 0xff);
+ *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(background->green & 0xff);
+ *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(background->blue & 0xff);
+ }
+ else
+ {
+ png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(v & 0xff);
+ v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 6)
+ {
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp+1));
+ png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
+ png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
+
+ if (r == trans_color->red && g == trans_color->green &&
+ b == trans_color->blue)
+ {
+ *sp = (png_byte)((background->red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(background->red & 0xff);
+ *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(background->green & 0xff);
+ *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(background->blue & 0xff);
+ }
+ }
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+ gamma_table != NULL)
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 2, dp++)
+ {
+ png_uint_16 a = *(sp + 1);
+
+ if (a == 0xff)
+ {
+ *dp = gamma_table[*sp];
+ }
+ else if (a == 0)
+ {
+ /* Background is already in screen gamma */
+ *dp = (png_byte)background->gray;
+ }
+ else
+ {
+ png_byte v, w;
+
+ v = gamma_to_1[*sp];
+ png_composite(w, v, a, background_1->gray);
+ *dp = gamma_from_1[w];
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 2, dp++)
+ {
+ png_byte a = *(sp + 1);
+
+ if (a == 0xff)
+ {
+ *dp = *sp;
+ }
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ else if (a == 0)
+ {
+ *dp = (png_byte)background->gray;
+ }
+ else
+ {
+ png_composite(*dp, *sp, a, background_1->gray);
+ }
+#else
+ *dp = (png_byte)background->gray;
+#endif
+ }
+ }
+ }
+ else /* if (png_ptr->bit_depth == 16) */
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+ gamma_16_to_1 != NULL)
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 4, dp += 2)
+ {
+ png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
+
+ if (a == (png_uint_16)0xffff)
+ {
+ png_uint_16 v;
+
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *dp = (png_byte)((v >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(v & 0xff);
+ }
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ else if (a == 0)
+#else
+ else
+#endif
+ {
+ /* Background is already in screen gamma */
+ *dp = (png_byte)((background->gray >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(background->gray & 0xff);
+ }
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ else
+ {
+ png_uint_16 g, v, w;
+
+ g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+ png_composite_16(v, g, a, background_1->gray);
+ w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
+ *dp = (png_byte)((w >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(w & 0xff);
+ }
+#endif
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 4, dp += 2)
+ {
+ png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
+ if (a == (png_uint_16)0xffff)
+ {
+ png_memcpy(dp, sp, 2);
+ }
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ else if (a == 0)
+#else
+ else
+#endif
+ {
+ *dp = (png_byte)((background->gray >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(background->gray & 0xff);
+ }
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ else
+ {
+ png_uint_16 g, v;
+
+ g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ png_composite_16(v, g, a, background_1->gray);
+ *dp = (png_byte)((v >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(v & 0xff);
+ }
+#endif
+ }
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+ gamma_table != NULL)
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 4, dp += 3)
+ {
+ png_byte a = *(sp + 3);
+
+ if (a == 0xff)
+ {
+ *dp = gamma_table[*sp];
+ *(dp + 1) = gamma_table[*(sp + 1)];
+ *(dp + 2) = gamma_table[*(sp + 2)];
+ }
+ else if (a == 0)
+ {
+ /* Background is already in screen gamma */
+ *dp = (png_byte)background->red;
+ *(dp + 1) = (png_byte)background->green;
+ *(dp + 2) = (png_byte)background->blue;
+ }
+ else
+ {
+ png_byte v, w;
+
+ v = gamma_to_1[*sp];
+ png_composite(w, v, a, background_1->red);
+ *dp = gamma_from_1[w];
+ v = gamma_to_1[*(sp + 1)];
+ png_composite(w, v, a, background_1->green);
+ *(dp + 1) = gamma_from_1[w];
+ v = gamma_to_1[*(sp + 2)];
+ png_composite(w, v, a, background_1->blue);
+ *(dp + 2) = gamma_from_1[w];
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 4, dp += 3)
+ {
+ png_byte a = *(sp + 3);
+
+ if (a == 0xff)
+ {
+ *dp = *sp;
+ *(dp + 1) = *(sp + 1);
+ *(dp + 2) = *(sp + 2);
+ }
+ else if (a == 0)
+ {
+ *dp = (png_byte)background->red;
+ *(dp + 1) = (png_byte)background->green;
+ *(dp + 2) = (png_byte)background->blue;
+ }
+ else
+ {
+ png_composite(*dp, *sp, a, background->red);
+ png_composite(*(dp + 1), *(sp + 1), a,
+ background->green);
+ png_composite(*(dp + 2), *(sp + 2), a,
+ background->blue);
+ }
+ }
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+ gamma_16_to_1 != NULL)
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 8, dp += 6)
+ {
+ png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+ << 8) + (png_uint_16)(*(sp + 7)));
+ if (a == (png_uint_16)0xffff)
+ {
+ png_uint_16 v;
+
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *dp = (png_byte)((v >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(v & 0xff);
+ v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ *(dp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(dp + 3) = (png_byte)(v & 0xff);
+ v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ *(dp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(dp + 5) = (png_byte)(v & 0xff);
+ }
+ else if (a == 0)
+ {
+ /* Background is already in screen gamma */
+ *dp = (png_byte)((background->red >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(background->red & 0xff);
+ *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
+ *(dp + 3) = (png_byte)(background->green & 0xff);
+ *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
+ *(dp + 5) = (png_byte)(background->blue & 0xff);
+ }
+ else
+ {
+ png_uint_16 v, w, x;
+
+ v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+ png_composite_16(w, v, a, background_1->red);
+ x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
+ *dp = (png_byte)((x >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(x & 0xff);
+ v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ png_composite_16(w, v, a, background_1->green);
+ x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
+ *(dp + 2) = (png_byte)((x >> 8) & 0xff);
+ *(dp + 3) = (png_byte)(x & 0xff);
+ v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ png_composite_16(w, v, a, background_1->blue);
+ x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8];
+ *(dp + 4) = (png_byte)((x >> 8) & 0xff);
+ *(dp + 5) = (png_byte)(x & 0xff);
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 8, dp += 6)
+ {
+ png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+ << 8) + (png_uint_16)(*(sp + 7)));
+ if (a == (png_uint_16)0xffff)
+ {
+ png_memcpy(dp, sp, 6);
+ }
+ else if (a == 0)
+ {
+ *dp = (png_byte)((background->red >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(background->red & 0xff);
+ *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
+ *(dp + 3) = (png_byte)(background->green & 0xff);
+ *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
+ *(dp + 5) = (png_byte)(background->blue & 0xff);
+ }
+ else
+ {
+ png_uint_16 v;
+
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+ png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+ + *(sp + 5));
+
+ png_composite_16(v, r, a, background->red);
+ *dp = (png_byte)((v >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(v & 0xff);
+ png_composite_16(v, g, a, background->green);
+ *(dp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(dp + 3) = (png_byte)(v & 0xff);
+ png_composite_16(v, b, a, background->blue);
+ *(dp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(dp + 5) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ }
+ break;
+ }
+ }
+
+ if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
+ {
+ row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
+ row_info->channels--;
+ row_info->pixel_depth = (png_byte)(row_info->channels *
+ row_info->bit_depth);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* Gamma correct the image, avoiding the alpha channel. Make sure
+ * you do this after you deal with the transparency issue on grayscale
+ * or RGB images. If your bit depth is 8, use gamma_table, if it
+ * is 16, use gamma_16_table and gamma_shift. Build these with
+ * build_gamma_table().
+ */
+void /* PRIVATE */
+png_do_gamma(png_row_infop row_info, png_bytep row,
+ png_bytep gamma_table, png_uint_16pp gamma_16_table,
+ int gamma_shift)
+{
+ png_bytep sp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_gamma");
+
+ if (
+ ((row_info->bit_depth <= 8 && gamma_table != NULL) ||
+ (row_info->bit_depth == 16 && gamma_16_table != NULL)))
+ {
+ switch (row_info->color_type)
+ {
+ case PNG_COLOR_TYPE_RGB:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ sp++;
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 4;
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp += 2;
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 4;
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_GRAY:
+ {
+ if (row_info->bit_depth == 2)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i += 4)
+ {
+ int a = *sp & 0xc0;
+ int b = *sp & 0x30;
+ int c = *sp & 0x0c;
+ int d = *sp & 0x03;
+
+ *sp = (png_byte)(
+ ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
+ ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
+ ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
+ ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
+ sp++;
+ }
+ }
+
+ if (row_info->bit_depth == 4)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i += 2)
+ {
+ int msb = *sp & 0xf0;
+ int lsb = *sp & 0x0f;
+
+ *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
+ | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
+ sp++;
+ }
+ }
+
+ else if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+ }
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ }
+ }
+ break;
+ }
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expands a palette row to an RGB or RGBA row depending
+ * upon whether you supply trans and num_trans.
+ */
+void /* PRIVATE */
+png_do_expand_palette(png_row_infop row_info, png_bytep row,
+ png_colorp palette, png_bytep trans_alpha, int num_trans)
+{
+ int shift, value;
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_expand_palette");
+
+ if (
+ row_info->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (row_info->bit_depth < 8)
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ sp = row + (png_size_t)((row_width - 1) >> 3);
+ dp = row + (png_size_t)row_width - 1;
+ shift = 7 - (int)((row_width + 7) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*sp >> shift) & 0x01)
+ *dp = 1;
+ else
+ *dp = 0;
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+ sp = row + (png_size_t)((row_width - 1) >> 2);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x03;
+ *dp = (png_byte)value;
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ sp = row + (png_size_t)((row_width - 1) >> 1);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((row_width & 0x01) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x0f;
+ *dp = (png_byte)value;
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift += 4;
+
+ dp--;
+ }
+ break;
+ }
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 8;
+ row_info->rowbytes = row_width;
+ }
+ switch (row_info->bit_depth)
+ {
+ case 8:
+ {
+ if (trans_alpha != NULL)
+ {
+ sp = row + (png_size_t)row_width - 1;
+ dp = row + (png_size_t)(row_width << 2) - 1;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if ((int)(*sp) >= num_trans)
+ *dp-- = 0xff;
+ else
+ *dp-- = trans_alpha[*sp];
+ *dp-- = palette[*sp].blue;
+ *dp-- = palette[*sp].green;
+ *dp-- = palette[*sp].red;
+ sp--;
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ row_info->color_type = 6;
+ row_info->channels = 4;
+ }
+ else
+ {
+ sp = row + (png_size_t)row_width - 1;
+ dp = row + (png_size_t)(row_width * 3) - 1;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *dp-- = palette[*sp].blue;
+ *dp-- = palette[*sp].green;
+ *dp-- = palette[*sp].red;
+ sp--;
+ }
+
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 24;
+ row_info->rowbytes = row_width * 3;
+ row_info->color_type = 2;
+ row_info->channels = 3;
+ }
+ break;
+ }
+ }
+ }
+}
+
+/* If the bit depth < 8, it is expanded to 8. Also, if the already
+ * expanded transparency value is supplied, an alpha channel is built.
+ */
+void /* PRIVATE */
+png_do_expand(png_row_infop row_info, png_bytep row,
+ png_color_16p trans_value)
+{
+ int shift, value;
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_expand");
+
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0);
+
+ if (row_info->bit_depth < 8)
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ gray = (png_uint_16)((gray&0x01)*0xff);
+ sp = row + (png_size_t)((row_width - 1) >> 3);
+ dp = row + (png_size_t)row_width - 1;
+ shift = 7 - (int)((row_width + 7) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*sp >> shift) & 0x01)
+ *dp = 0xff;
+ else
+ *dp = 0;
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+ gray = (png_uint_16)((gray&0x03)*0x55);
+ sp = row + (png_size_t)((row_width - 1) >> 2);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x03;
+ *dp = (png_byte)(value | (value << 2) | (value << 4) |
+ (value << 6));
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ gray = (png_uint_16)((gray&0x0f)*0x11);
+ sp = row + (png_size_t)((row_width - 1) >> 1);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x0f;
+ *dp = (png_byte)(value | (value << 4));
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift = 4;
+
+ dp--;
+ }
+ break;
+ }
+ }
+
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 8;
+ row_info->rowbytes = row_width;
+ }
+
+ if (trans_value != NULL)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ gray = gray & 0xff;
+ sp = row + (png_size_t)row_width - 1;
+ dp = row + (png_size_t)(row_width << 1) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*sp == gray)
+ *dp-- = 0;
+ else
+ *dp-- = 0xff;
+ *dp-- = *sp--;
+ }
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ png_byte gray_high = (gray >> 8) & 0xff;
+ png_byte gray_low = gray & 0xff;
+ sp = row + row_info->rowbytes - 1;
+ dp = row + (row_info->rowbytes << 1) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*(sp - 1) == gray_high && *(sp) == gray_low)
+ {
+ *dp-- = 0;
+ *dp-- = 0;
+ }
+ else
+ {
+ *dp-- = 0xff;
+ *dp-- = 0xff;
+ }
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+
+ row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+ row_info->channels = 2;
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_width);
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ png_byte red = trans_value->red & 0xff;
+ png_byte green = trans_value->green & 0xff;
+ png_byte blue = trans_value->blue & 0xff;
+ sp = row + (png_size_t)row_info->rowbytes - 1;
+ dp = row + (png_size_t)(row_width << 2) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
+ *dp-- = 0;
+ else
+ *dp-- = 0xff;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ png_byte red_high = (trans_value->red >> 8) & 0xff;
+ png_byte green_high = (trans_value->green >> 8) & 0xff;
+ png_byte blue_high = (trans_value->blue >> 8) & 0xff;
+ png_byte red_low = trans_value->red & 0xff;
+ png_byte green_low = trans_value->green & 0xff;
+ png_byte blue_low = trans_value->blue & 0xff;
+ sp = row + row_info->rowbytes - 1;
+ dp = row + (png_size_t)(row_width << 3) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*(sp - 5) == red_high &&
+ *(sp - 4) == red_low &&
+ *(sp - 3) == green_high &&
+ *(sp - 2) == green_low &&
+ *(sp - 1) == blue_high &&
+ *(sp ) == blue_low)
+ {
+ *dp-- = 0;
+ *dp-- = 0;
+ }
+ else
+ {
+ *dp-- = 0xff;
+ *dp-- = 0xff;
+ }
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+ row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+ row_info->channels = 4;
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+void /* PRIVATE */
+png_do_quantize(png_row_infop row_info, png_bytep row,
+ png_bytep palette_lookup, png_bytep quantize_lookup)
+{
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_quantize");
+
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
+ palette_lookup && row_info->bit_depth == 8)
+ {
+ int r, g, b, p;
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ r = *sp++;
+ g = *sp++;
+ b = *sp++;
+
+ /* This looks real messy, but the compiler will reduce
+ * it down to a reasonable formula. For example, with
+ * 5 bits per color, we get:
+ * p = (((r >> 3) & 0x1f) << 10) |
+ * (((g >> 3) & 0x1f) << 5) |
+ * ((b >> 3) & 0x1f);
+ */
+ p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+ ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+ (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+ (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+ ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+ (PNG_QUANTIZE_BLUE_BITS)) |
+ ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+ ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
+
+ *dp++ = palette_lookup[p];
+ }
+ row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+ row_info->channels = 1;
+ row_info->pixel_depth = row_info->bit_depth;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
+ palette_lookup != NULL && row_info->bit_depth == 8)
+ {
+ int r, g, b, p;
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ r = *sp++;
+ g = *sp++;
+ b = *sp++;
+ sp++;
+
+ p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+ ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+ (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+ (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+ ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+ (PNG_QUANTIZE_BLUE_BITS)) |
+ ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+ ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
+
+ *dp++ = palette_lookup[p];
+ }
+ row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+ row_info->channels = 1;
+ row_info->pixel_depth = row_info->bit_depth;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
+ quantize_lookup && row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ *sp = quantize_lookup[*sp];
+ }
+ }
+ }
+}
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+#ifdef PNG_READ_GAMMA_SUPPORTED
+static PNG_CONST int png_gamma_shift[] =
+ {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00};
+
+/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit
+ * tables, we don't make a full table if we are reducing to 8-bit in
+ * the future. Note also how the gamma_16 tables are segmented so that
+ * we don't need to allocate > 64K chunks for a full 16-bit table.
+ *
+ * See the PNG extensions document for an integer algorithm for creating
+ * the gamma tables. Maybe we will implement that here someday.
+ *
+ * We should only reach this point if
+ *
+ * the file_gamma is known (i.e., the gAMA or sRGB chunk is present,
+ * or the application has provided a file_gamma)
+ *
+ * AND
+ * {
+ * the screen_gamma is known
+ *
+ * OR
+ *
+ * RGB_to_gray transformation is being performed
+ * }
+ *
+ * AND
+ * {
+ * the screen_gamma is different from the reciprocal of the
+ * file_gamma by more than the specified threshold
+ *
+ * OR
+ *
+ * a background color has been specified and the file_gamma
+ * and screen_gamma are not 1.0, within the specified threshold.
+ * }
+ */
+
+void /* PRIVATE */
+png_build_gamma_table(png_structp png_ptr, png_byte bit_depth)
+{
+ png_debug(1, "in png_build_gamma_table");
+
+ if (bit_depth <= 8)
+ {
+ int i;
+ double g;
+
+ if (png_ptr->screen_gamma > .000001)
+ g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+
+ else
+ g = 1.0;
+
+ png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)256);
+
+ for (i = 0; i < 256; i++)
+ {
+ png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0,
+ g) * 255.0 + .5);
+ }
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY))
+ {
+
+ g = 1.0 / (png_ptr->gamma);
+
+ png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)256);
+
+ for (i = 0; i < 256; i++)
+ {
+ png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0,
+ g) * 255.0 + .5);
+ }
+
+
+ png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)256);
+
+ if (png_ptr->screen_gamma > 0.000001)
+ g = 1.0 / png_ptr->screen_gamma;
+
+ else
+ g = png_ptr->gamma; /* Probably doing rgb_to_gray */
+
+ for (i = 0; i < 256; i++)
+ {
+ png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0,
+ g) * 255.0 + .5);
+
+ }
+ }
+#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
+ }
+ else
+ {
+ double g;
+ int i, j, shift, num;
+ int sig_bit;
+ png_uint_32 ig;
+
+ if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
+ {
+ sig_bit = (int)png_ptr->sig_bit.red;
+
+ if ((int)png_ptr->sig_bit.green > sig_bit)
+ sig_bit = png_ptr->sig_bit.green;
+
+ if ((int)png_ptr->sig_bit.blue > sig_bit)
+ sig_bit = png_ptr->sig_bit.blue;
+ }
+ else
+ {
+ sig_bit = (int)png_ptr->sig_bit.gray;
+ }
+
+ if (sig_bit > 0)
+ shift = 16 - sig_bit;
+
+ else
+ shift = 0;
+
+ if (png_ptr->transformations & PNG_16_TO_8)
+ {
+ if (shift < (16 - PNG_MAX_GAMMA_8))
+ shift = (16 - PNG_MAX_GAMMA_8);
+ }
+
+ if (shift > 8)
+ shift = 8;
+
+ if (shift < 0)
+ shift = 0;
+
+ png_ptr->gamma_shift = (png_byte)shift;
+
+ num = (1 << (8 - shift));
+
+ if (png_ptr->screen_gamma > .000001)
+ g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+ else
+ g = 1.0;
+
+ png_ptr->gamma_16_table = (png_uint_16pp)png_calloc(png_ptr,
+ (png_uint_32)(num * png_sizeof(png_uint_16p)));
+
+ if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND))
+ {
+ double fin, fout;
+ png_uint_32 last, max;
+
+ for (i = 0; i < num; i++)
+ {
+ png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(256 * png_sizeof(png_uint_16)));
+ }
+
+ g = 1.0 / g;
+ last = 0;
+ for (i = 0; i < 256; i++)
+ {
+ fout = ((double)i + 0.5) / 256.0;
+ fin = pow(fout, g);
+ max = (png_uint_32)(fin * (double)((png_uint_32)num << 8));
+ while (last <= max)
+ {
+ png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
+ [(int)(last >> (8 - shift))] = (png_uint_16)(
+ (png_uint_16)i | ((png_uint_16)i << 8));
+ last++;
+ }
+ }
+ while (last < ((png_uint_32)num << 8))
+ {
+ png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
+ [(int)(last >> (8 - shift))] = (png_uint_16)65535L;
+ last++;
+ }
+ }
+ else
+ {
+ for (i = 0; i < num; i++)
+ {
+ png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(256 * png_sizeof(png_uint_16)));
+
+ ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4);
+
+ for (j = 0; j < 256; j++)
+ {
+ png_ptr->gamma_16_table[i][j] =
+ (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
+ 65535.0, g) * 65535.0 + .5);
+ }
+ }
+ }
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))
+ {
+
+ g = 1.0 / (png_ptr->gamma);
+
+ png_ptr->gamma_16_to_1 = (png_uint_16pp)png_calloc(png_ptr,
+ (png_uint_32)(num * png_sizeof(png_uint_16p )));
+
+ for (i = 0; i < num; i++)
+ {
+ png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(256 * png_sizeof(png_uint_16)));
+
+ ig = (((png_uint_32)i *
+ (png_uint_32)png_gamma_shift[shift]) >> 4);
+ for (j = 0; j < 256; j++)
+ {
+ png_ptr->gamma_16_to_1[i][j] =
+ (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
+ 65535.0, g) * 65535.0 + .5);
+ }
+ }
+
+ if (png_ptr->screen_gamma > 0.000001)
+ g = 1.0 / png_ptr->screen_gamma;
+
+ else
+ g = png_ptr->gamma; /* Probably doing rgb_to_gray */
+
+ png_ptr->gamma_16_from_1 = (png_uint_16pp)png_calloc(png_ptr,
+ (png_uint_32)(num * png_sizeof(png_uint_16p)));
+
+ for (i = 0; i < num; i++)
+ {
+ png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(256 * png_sizeof(png_uint_16)));
+
+ ig = (((png_uint_32)i *
+ (png_uint_32)png_gamma_shift[shift]) >> 4);
+
+ for (j = 0; j < 256; j++)
+ {
+ png_ptr->gamma_16_from_1[i][j] =
+ (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
+ 65535.0, g) * 65535.0 + .5);
+ }
+ }
+ }
+#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
+ }
+}
+#endif
+/* To do: install integer version of png_build_gamma_table here */
+#endif
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Undoes intrapixel differencing */
+void /* PRIVATE */
+png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_read_intrapixel");
+
+ if (
+ (row_info->color_type & PNG_COLOR_MASK_COLOR))
+ {
+ int bytes_per_pixel;
+ png_uint_32 row_width = row_info->width;
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 3;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 4;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ *(rp) = (png_byte)((256 + *rp + *(rp+1))&0xff);
+ *(rp+2) = (png_byte)((256 + *(rp+2) + *(rp+1))&0xff);
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 6;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 8;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
+ png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
+ png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
+ png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL);
+ png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL);
+ *(rp ) = (png_byte)((red >> 8) & 0xff);
+ *(rp+1) = (png_byte)(red & 0xff);
+ *(rp+4) = (png_byte)((blue >> 8) & 0xff);
+ *(rp+5) = (png_byte)(blue & 0xff);
+ }
+ }
+ }
+}
+#endif /* PNG_MNG_FEATURES_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED */
--- /dev/null
+
+/* pngrutil.c - utilities to read a PNG file
+ *
+ * Last changed in libpng 1.4.4 [August 26, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that are only called from within
+ * libpng itself during the course of reading an image.
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#ifdef PNG_READ_SUPPORTED
+#include "pngpriv.h"
+
+# define png_strtod(p,a,b) strtod(a,b)
+png_uint_32 PNGAPI
+png_get_uint_31(png_structp png_ptr, png_bytep buf)
+{
+ png_uint_32 i = png_get_uint_32(buf);
+ if (i > PNG_UINT_31_MAX)
+ png_error(png_ptr, "PNG unsigned integer out of range");
+ return (i);
+}
+#ifndef PNG_USE_READ_MACROS
+/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
+png_uint_32 (PNGAPI
+png_get_uint_32)(png_bytep buf)
+{
+ png_uint_32 i =
+ ((png_uint_32)(*(buf )) << 24) +
+ ((png_uint_32)(*(buf + 1)) << 16) +
+ ((png_uint_32)(*(buf + 2)) << 8) +
+ ((png_uint_32)(*(buf + 3)) ) ;
+
+ return (i);
+}
+
+/* Grab a signed 32-bit integer from a buffer in big-endian format. The
+ * data is stored in the PNG file in two's complement format and there
+ * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore
+ * the following code does a two's complement to native conversion.
+ */
+png_int_32 (PNGAPI
+png_get_int_32)(png_bytep buf)
+{
+ png_uint_32 u = png_get_uint_32(buf);
+ if ((u & 0x80000000) == 0) /* non-negative */
+ return u;
+
+ u = (u ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */
+ return -(png_int_32)u;
+}
+
+/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
+png_uint_16 (PNGAPI
+png_get_uint_16)(png_bytep buf)
+{
+ png_uint_16 i =
+ ((png_uint_32)(*buf) << 8) +
+ ((png_uint_32)(*(buf + 1)));
+
+ return (i);
+}
+#endif /* PNG_USE_READ_MACROS */
+
+/* Read the chunk header (length + type name).
+ * Put the type name into png_ptr->chunk_name, and return the length.
+ */
+png_uint_32 /* PRIVATE */
+png_read_chunk_header(png_structp png_ptr)
+{
+ png_byte buf[8];
+ png_uint_32 length;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the chunk header is being read.
+ * PNG_IO_CHUNK_HDR requires a single I/O call.
+ */
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR;
+#endif
+
+ /* Read the length and the chunk name */
+ png_read_data(png_ptr, buf, 8);
+ length = png_get_uint_31(png_ptr, buf);
+
+ /* Put the chunk name into png_ptr->chunk_name */
+ png_memcpy(png_ptr->chunk_name, buf + 4, 4);
+
+ png_debug2(0, "Reading %s chunk, length = %lu",
+ png_ptr->chunk_name, length);
+
+ /* Reset the crc and run it over the chunk name */
+ png_reset_crc(png_ptr);
+ png_calculate_crc(png_ptr, png_ptr->chunk_name, 4);
+
+ /* Check to see if chunk name is valid */
+ png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that chunk data will (possibly) be read.
+ * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
+ */
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
+#endif
+
+ return length;
+}
+
+/* Read data, and (optionally) run it through the CRC. */
+void /* PRIVATE */
+png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
+{
+ if (png_ptr == NULL)
+ return;
+ png_read_data(png_ptr, buf, length);
+ png_calculate_crc(png_ptr, buf, length);
+}
+
+/* Optionally skip data and then check the CRC. Depending on whether we
+ * are reading a ancillary or critical chunk, and how the program has set
+ * things up, we may calculate the CRC on the data and print a message.
+ * Returns '1' if there was a CRC error, '0' otherwise.
+ */
+int /* PRIVATE */
+png_crc_finish(png_structp png_ptr, png_uint_32 skip)
+{
+ png_size_t i;
+ png_size_t istop = png_ptr->zbuf_size;
+
+ for (i = (png_size_t)skip; i > istop; i -= istop)
+ {
+ png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
+ }
+ if (i)
+ {
+ png_crc_read(png_ptr, png_ptr->zbuf, i);
+ }
+
+ if (png_crc_error(png_ptr))
+ {
+ if (((png_ptr->chunk_name[0] & 0x20) && /* Ancillary */
+ !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) ||
+ (!(png_ptr->chunk_name[0] & 0x20) && /* Critical */
+ (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)))
+ {
+ png_chunk_warning(png_ptr, "CRC error");
+ }
+ else
+ {
+ png_chunk_benign_error(png_ptr, "CRC error");
+ return (0);
+ }
+ return (1);
+ }
+
+ return (0);
+}
+
+/* Compare the CRC stored in the PNG file with that calculated by libpng from
+ * the data it has read thus far.
+ */
+int /* PRIVATE */
+png_crc_error(png_structp png_ptr)
+{
+ png_byte crc_bytes[4];
+ png_uint_32 crc;
+ int need_crc = 1;
+
+ if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+ (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+ need_crc = 0;
+ }
+ else /* critical */
+ {
+ if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
+ need_crc = 0;
+ }
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the chunk CRC is being read */
+ /* PNG_IO_CHUNK_CRC requires the I/O to be done at once */
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC;
+#endif
+
+ png_read_data(png_ptr, crc_bytes, 4);
+
+ if (need_crc)
+ {
+ crc = png_get_uint_32(crc_bytes);
+ return ((int)(crc != png_ptr->crc));
+ }
+ else
+ return (0);
+}
+
+#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \
+ defined(PNG_READ_iCCP_SUPPORTED)
+static png_size_t
+png_inflate(png_structp png_ptr, const png_byte *data, png_size_t size,
+ png_bytep output, png_size_t output_size)
+{
+ png_size_t count = 0;
+
+ png_ptr->zstream.next_in = (png_bytep)data; /* const_cast: VALID */
+ png_ptr->zstream.avail_in = size;
+
+ while (1)
+ {
+ int ret, avail;
+
+ /* Reset the output buffer each time round - we empty it
+ * after every inflate call.
+ */
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = png_ptr->zbuf_size;
+
+ ret = inflate(&png_ptr->zstream, Z_NO_FLUSH);
+ avail = png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+
+ /* First copy/count any new output - but only if we didn't
+ * get an error code.
+ */
+ if ((ret == Z_OK || ret == Z_STREAM_END) && avail > 0)
+ {
+ if (output != 0 && output_size > count)
+ {
+ int copy = output_size - count;
+ if (avail < copy) copy = avail;
+ png_memcpy(output + count, png_ptr->zbuf, copy);
+ }
+ count += avail;
+ }
+
+ if (ret == Z_OK)
+ continue;
+
+ /* Termination conditions - always reset the zstream, it
+ * must be left in inflateInit state.
+ */
+ png_ptr->zstream.avail_in = 0;
+ inflateReset(&png_ptr->zstream);
+
+ if (ret == Z_STREAM_END)
+ return count; /* NOTE: may be zero. */
+
+ /* Now handle the error codes - the API always returns 0
+ * and the error message is dumped into the uncompressed
+ * buffer if available.
+ */
+ {
+ PNG_CONST char *msg;
+ if (png_ptr->zstream.msg != 0)
+ msg = png_ptr->zstream.msg;
+ else
+ {
+#ifdef PNG_STDIO_SUPPORTED
+ char umsg[52];
+
+ switch (ret)
+ {
+ case Z_BUF_ERROR:
+ msg = "Buffer error in compressed datastream in %s chunk";
+ break;
+ case Z_DATA_ERROR:
+ msg = "Data error in compressed datastream in %s chunk";
+ break;
+ default:
+ msg = "Incomplete compressed datastream in %s chunk";
+ break;
+ }
+
+ png_snprintf(umsg, sizeof umsg, msg, png_ptr->chunk_name);
+ msg = umsg;
+#else
+ msg = "Damaged compressed datastream in chunk other than IDAT";
+#endif
+ }
+
+ png_warning(png_ptr, msg);
+ }
+
+ /* 0 means an error - notice that this code simple ignores
+ * zero length compressed chunks as a result.
+ */
+ return 0;
+ }
+}
+
+/*
+ * Decompress trailing data in a chunk. The assumption is that chunkdata
+ * points at an allocated area holding the contents of a chunk with a
+ * trailing compressed part. What we get back is an allocated area
+ * holding the original prefix part and an uncompressed version of the
+ * trailing part (the malloc area passed in is freed).
+ */
+void /* PRIVATE */
+png_decompress_chunk(png_structp png_ptr, int comp_type,
+ png_size_t chunklength,
+ png_size_t prefix_size, png_size_t *newlength)
+{
+ /* The caller should guarantee this */
+ if (prefix_size > chunklength)
+ {
+ /* The recovery is to delete the chunk. */
+ png_warning(png_ptr, "invalid chunklength");
+ prefix_size = 0; /* To delete everything */
+ }
+
+ else if (comp_type == PNG_COMPRESSION_TYPE_BASE)
+ {
+ png_size_t expanded_size = png_inflate(png_ptr,
+ (png_bytep)(png_ptr->chunkdata + prefix_size),
+ chunklength - prefix_size,
+ 0/*output*/, 0/*output size*/);
+
+ /* Now check the limits on this chunk - if the limit fails the
+ * compressed data will be removed, the prefix will remain.
+ */
+#ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+ if (png_ptr->user_chunk_malloc_max &&
+ (prefix_size + expanded_size >= png_ptr->user_chunk_malloc_max - 1))
+#else
+# ifdef PNG_USER_CHUNK_MALLOC_MAX
+ if ((PNG_USER_CHUNK_MALLOC_MAX > 0) &&
+ prefix_size + expanded_size >= PNG_USER_CHUNK_MALLOC_MAX - 1)
+# endif
+#endif
+ png_warning(png_ptr, "Exceeded size limit while expanding chunk");
+
+ /* If the size is zero either there was an error and a message
+ * has already been output (warning) or the size really is zero
+ * and we have nothing to do - the code will exit through the
+ * error case below.
+ */
+#if defined(PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED) || \
+ defined(PNG_USER_CHUNK_MALLOC_MAX)
+ else
+#endif
+ if (expanded_size > 0)
+ {
+ /* Success (maybe) - really uncompress the chunk. */
+ png_size_t new_size = 0;
+ png_charp text = png_malloc_warn(png_ptr,
+ prefix_size + expanded_size + 1);
+
+ if (text != NULL)
+ {
+ png_memcpy(text, png_ptr->chunkdata, prefix_size);
+ new_size = png_inflate(png_ptr,
+ (png_bytep)(png_ptr->chunkdata + prefix_size),
+ chunklength - prefix_size,
+ (png_bytep)(text + prefix_size), expanded_size);
+ text[prefix_size + expanded_size] = 0; /* just in case */
+
+ if (new_size == expanded_size)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = text;
+ *newlength = prefix_size + expanded_size;
+ return; /* The success return! */
+ }
+
+ png_warning(png_ptr, "png_inflate logic error");
+ png_free(png_ptr, text);
+ }
+ else
+ png_warning(png_ptr, "Not enough memory to decompress chunk");
+ }
+ }
+
+ else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
+ {
+#ifdef PNG_STDIO_SUPPORTED
+ char umsg[50];
+
+ png_snprintf(umsg, sizeof umsg, "Unknown zTXt compression type %d",
+ comp_type);
+ png_warning(png_ptr, umsg);
+#else
+ png_warning(png_ptr, "Unknown zTXt compression type");
+#endif
+
+ /* The recovery is to simply drop the data. */
+ }
+
+ /* Generic error return - leave the prefix, delete the compressed
+ * data, reallocate the chunkdata to remove the potentially large
+ * amount of compressed data.
+ */
+ {
+ png_charp text = png_malloc_warn(png_ptr, prefix_size + 1);
+ if (text != NULL)
+ {
+ if (prefix_size > 0)
+ png_memcpy(text, png_ptr->chunkdata, prefix_size);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = text;
+
+ /* This is an extra zero in the 'uncompressed' part. */
+ *(png_ptr->chunkdata + prefix_size) = 0x00;
+ }
+ /* Ignore a malloc error here - it is safe. */
+ }
+
+ *newlength = prefix_size;
+}
+#endif
+
+/* Read and check the IDHR chunk */
+void /* PRIVATE */
+png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte buf[13];
+ png_uint_32 width, height;
+ int bit_depth, color_type, compression_type, filter_type;
+ int interlace_type;
+
+ png_debug(1, "in png_handle_IHDR");
+
+ if (png_ptr->mode & PNG_HAVE_IHDR)
+ png_error(png_ptr, "Out of place IHDR");
+
+ /* Check the length */
+ if (length != 13)
+ png_error(png_ptr, "Invalid IHDR chunk");
+
+ png_ptr->mode |= PNG_HAVE_IHDR;
+
+ png_crc_read(png_ptr, buf, 13);
+ png_crc_finish(png_ptr, 0);
+
+ width = png_get_uint_31(png_ptr, buf);
+ height = png_get_uint_31(png_ptr, buf + 4);
+ bit_depth = buf[8];
+ color_type = buf[9];
+ compression_type = buf[10];
+ filter_type = buf[11];
+ interlace_type = buf[12];
+
+ /* Set internal variables */
+ png_ptr->width = width;
+ png_ptr->height = height;
+ png_ptr->bit_depth = (png_byte)bit_depth;
+ png_ptr->interlaced = (png_byte)interlace_type;
+ png_ptr->color_type = (png_byte)color_type;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ png_ptr->filter_type = (png_byte)filter_type;
+#endif
+ png_ptr->compression_type = (png_byte)compression_type;
+
+ /* Find number of channels */
+ switch (png_ptr->color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ case PNG_COLOR_TYPE_PALETTE:
+ png_ptr->channels = 1;
+ break;
+
+ case PNG_COLOR_TYPE_RGB:
+ png_ptr->channels = 3;
+ break;
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ png_ptr->channels = 2;
+ break;
+
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ png_ptr->channels = 4;
+ break;
+ }
+
+ /* Set up other useful info */
+ png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
+ png_ptr->channels);
+ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
+ png_debug1(3, "bit_depth = %d", png_ptr->bit_depth);
+ png_debug1(3, "channels = %d", png_ptr->channels);
+ png_debug1(3, "rowbytes = %lu", png_ptr->rowbytes);
+ png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
+ color_type, interlace_type, compression_type, filter_type);
+}
+
+/* Read and check the palette */
+void /* PRIVATE */
+png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_color palette[PNG_MAX_PALETTE_LENGTH];
+ int num, i;
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ png_colorp pal_ptr;
+#endif
+
+ png_debug(1, "in png_handle_PLTE");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before PLTE");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid PLTE after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ png_error(png_ptr, "Duplicate PLTE chunk");
+
+ png_ptr->mode |= PNG_HAVE_PLTE;
+
+ if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
+ {
+ png_warning(png_ptr,
+ "Ignoring PLTE chunk in grayscale PNG");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+ if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+#endif
+
+ if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
+ {
+ if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ png_warning(png_ptr, "Invalid palette chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else
+ {
+ png_error(png_ptr, "Invalid palette chunk");
+ }
+ }
+
+ num = (int)length / 3;
+
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
+ {
+ png_byte buf[3];
+
+ png_crc_read(png_ptr, buf, 3);
+ pal_ptr->red = buf[0];
+ pal_ptr->green = buf[1];
+ pal_ptr->blue = buf[2];
+ }
+#else
+ for (i = 0; i < num; i++)
+ {
+ png_byte buf[3];
+
+ png_crc_read(png_ptr, buf, 3);
+ /* Don't depend upon png_color being any order */
+ palette[i].red = buf[0];
+ palette[i].green = buf[1];
+ palette[i].blue = buf[2];
+ }
+#endif
+
+ /* If we actually NEED the PLTE chunk (ie for a paletted image), we do
+ * whatever the normal CRC configuration tells us. However, if we
+ * have an RGB image, the PLTE can be considered ancillary, so
+ * we will act as though it is.
+ */
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#endif
+ {
+ png_crc_finish(png_ptr, 0);
+ }
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+ else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */
+ {
+ /* If we don't want to use the data from an ancillary chunk,
+ we have two options: an error abort, or a warning and we
+ ignore the data in this chunk (which should be OK, since
+ it's considered ancillary for a RGB or RGBA image). */
+ if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
+ {
+ if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
+ {
+ png_chunk_benign_error(png_ptr, "CRC error");
+ }
+ else
+ {
+ png_chunk_warning(png_ptr, "CRC error");
+ return;
+ }
+ }
+ /* Otherwise, we (optionally) emit a warning and use the chunk. */
+ else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
+ {
+ png_chunk_warning(png_ptr, "CRC error");
+ }
+ }
+#endif
+
+ png_set_PLTE(png_ptr, info_ptr, palette, num);
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+ {
+ if (png_ptr->num_trans > (png_uint_16)num)
+ {
+ png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
+ png_ptr->num_trans = (png_uint_16)num;
+ }
+ if (info_ptr->num_trans > (png_uint_16)num)
+ {
+ png_warning(png_ptr, "Truncating incorrect info tRNS chunk length");
+ info_ptr->num_trans = (png_uint_16)num;
+ }
+ }
+ }
+#endif
+
+}
+
+void /* PRIVATE */
+png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_debug(1, "in png_handle_IEND");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
+ {
+ png_error(png_ptr, "No image in file");
+ }
+
+ png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
+
+ if (length != 0)
+ {
+ png_warning(png_ptr, "Incorrect IEND chunk length");
+ }
+ png_crc_finish(png_ptr, length);
+
+ info_ptr = info_ptr; /* Quiet compiler warnings about unused info_ptr */
+}
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+void /* PRIVATE */
+png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_fixed_point igamma;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ float file_gamma;
+#endif
+ png_byte buf[4];
+
+ png_debug(1, "in png_handle_gAMA");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before gAMA");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid gAMA after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place gAMA chunk");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+#ifdef PNG_READ_sRGB_SUPPORTED
+ && !(info_ptr->valid & PNG_INFO_sRGB)
+#endif
+ )
+ {
+ png_warning(png_ptr, "Duplicate gAMA chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 4)
+ {
+ png_warning(png_ptr, "Incorrect gAMA chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 4);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ igamma = (png_fixed_point)png_get_uint_32(buf);
+ /* Check for zero gamma */
+ if (igamma == 0)
+ {
+ png_warning(png_ptr,
+ "Ignoring gAMA chunk with gamma=0");
+ return;
+ }
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
+ if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
+ {
+ png_warning(png_ptr,
+ "Ignoring incorrect gAMA value when sRGB is also present");
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+ fprintf(stderr, "gamma = (%d/100000)", (int)igamma);
+#endif
+ return;
+ }
+#endif /* PNG_READ_sRGB_SUPPORTED */
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ file_gamma = (float)igamma / (float)100000.0;
+# ifdef PNG_READ_GAMMA_SUPPORTED
+ png_ptr->gamma = file_gamma;
+# endif
+ png_set_gAMA(png_ptr, info_ptr, file_gamma);
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
+#endif
+}
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+void /* PRIVATE */
+png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_size_t truelen;
+ png_byte buf[4];
+
+ png_debug(1, "in png_handle_sBIT");
+
+ buf[0] = buf[1] = buf[2] = buf[3] = 0;
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sBIT");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sBIT after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ {
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place sBIT chunk");
+ }
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
+ {
+ png_warning(png_ptr, "Duplicate sBIT chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ truelen = 3;
+ else
+ truelen = (png_size_t)png_ptr->channels;
+
+ if (length != truelen || length > 4)
+ {
+ png_warning(png_ptr, "Incorrect sBIT chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, truelen);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
+ {
+ png_ptr->sig_bit.red = buf[0];
+ png_ptr->sig_bit.green = buf[1];
+ png_ptr->sig_bit.blue = buf[2];
+ png_ptr->sig_bit.alpha = buf[3];
+ }
+ else
+ {
+ png_ptr->sig_bit.gray = buf[0];
+ png_ptr->sig_bit.red = buf[0];
+ png_ptr->sig_bit.green = buf[0];
+ png_ptr->sig_bit.blue = buf[0];
+ png_ptr->sig_bit.alpha = buf[1];
+ }
+ png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
+}
+#endif
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+void /* PRIVATE */
+png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte buf[32];
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
+#endif
+ png_fixed_point int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
+ int_y_green, int_x_blue, int_y_blue;
+
+ png_uint_32 uint_x, uint_y;
+
+ png_debug(1, "in png_handle_cHRM");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before cHRM");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid cHRM after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Missing PLTE before cHRM");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
+#ifdef PNG_READ_sRGB_SUPPORTED
+ && !(info_ptr->valid & PNG_INFO_sRGB)
+#endif
+ )
+ {
+ png_warning(png_ptr, "Duplicate cHRM chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 32)
+ {
+ png_warning(png_ptr, "Incorrect cHRM chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 32);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ uint_x = png_get_uint_32(buf);
+ uint_y = png_get_uint_32(buf + 4);
+ int_x_white = (png_fixed_point)uint_x;
+ int_y_white = (png_fixed_point)uint_y;
+
+ uint_x = png_get_uint_32(buf + 8);
+ uint_y = png_get_uint_32(buf + 12);
+ int_x_red = (png_fixed_point)uint_x;
+ int_y_red = (png_fixed_point)uint_y;
+
+ uint_x = png_get_uint_32(buf + 16);
+ uint_y = png_get_uint_32(buf + 20);
+ int_x_green = (png_fixed_point)uint_x;
+ int_y_green = (png_fixed_point)uint_y;
+
+ uint_x = png_get_uint_32(buf + 24);
+ uint_y = png_get_uint_32(buf + 28);
+ int_x_blue = (png_fixed_point)uint_x;
+ int_y_blue = (png_fixed_point)uint_y;
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ white_x = (float)int_x_white / (float)100000.0;
+ white_y = (float)int_y_white / (float)100000.0;
+ red_x = (float)int_x_red / (float)100000.0;
+ red_y = (float)int_y_red / (float)100000.0;
+ green_x = (float)int_x_green / (float)100000.0;
+ green_y = (float)int_y_green / (float)100000.0;
+ blue_x = (float)int_x_blue / (float)100000.0;
+ blue_y = (float)int_y_blue / (float)100000.0;
+#endif
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+ if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
+ {
+ if (PNG_OUT_OF_RANGE(int_x_white, 31270, 1000) ||
+ PNG_OUT_OF_RANGE(int_y_white, 32900, 1000) ||
+ PNG_OUT_OF_RANGE(int_x_red, 64000L, 1000) ||
+ PNG_OUT_OF_RANGE(int_y_red, 33000, 1000) ||
+ PNG_OUT_OF_RANGE(int_x_green, 30000, 1000) ||
+ PNG_OUT_OF_RANGE(int_y_green, 60000L, 1000) ||
+ PNG_OUT_OF_RANGE(int_x_blue, 15000, 1000) ||
+ PNG_OUT_OF_RANGE(int_y_blue, 6000, 1000))
+ {
+ png_warning(png_ptr,
+ "Ignoring incorrect cHRM value when sRGB is also present");
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ fprintf(stderr, "wx=%f, wy=%f, rx=%f, ry=%f\n",
+ white_x, white_y, red_x, red_y);
+ fprintf(stderr, "gx=%f, gy=%f, bx=%f, by=%f\n",
+ green_x, green_y, blue_x, blue_y);
+#else
+ fprintf(stderr, "wx=%ld, wy=%ld, rx=%ld, ry=%ld\n",
+ (long)int_x_white, (long)int_y_white,
+ (long)int_x_red, (long)int_y_red);
+ fprintf(stderr, "gx=%ld, gy=%ld, bx=%ld, by=%ld\n",
+ (long)int_x_green, (long)int_y_green,
+ (long)int_x_blue, (long)int_y_blue);
+#endif
+#endif /* PNG_CONSOLE_IO_SUPPORTED */
+ }
+ return;
+ }
+#endif /* PNG_READ_sRGB_SUPPORTED */
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ png_set_cHRM(png_ptr, info_ptr,
+ white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_set_cHRM_fixed(png_ptr, info_ptr,
+ int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
+ int_y_green, int_x_blue, int_y_blue);
+#endif
+}
+#endif
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+void /* PRIVATE */
+png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ int intent;
+ png_byte buf[1];
+
+ png_debug(1, "in png_handle_sRGB");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sRGB");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sRGB after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place sRGB chunk");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
+ {
+ png_warning(png_ptr, "Duplicate sRGB chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 1)
+ {
+ png_warning(png_ptr, "Incorrect sRGB chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 1);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ intent = buf[0];
+ /* Check for bad intent */
+ if (intent >= PNG_sRGB_INTENT_LAST)
+ {
+ png_warning(png_ptr, "Unknown sRGB intent");
+ return;
+ }
+
+#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
+ {
+ png_fixed_point igamma;
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ igamma=info_ptr->int_gamma;
+#else
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+ igamma=(png_fixed_point)(info_ptr->gamma * 100000.);
+# endif
+#endif
+ if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
+ {
+ png_warning(png_ptr,
+ "Ignoring incorrect gAMA value when sRGB is also present");
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+# ifdef PNG_FIXED_POINT_SUPPORTED
+ fprintf(stderr, "incorrect gamma=(%d/100000)\n",
+ (int)png_ptr->int_gamma);
+# else
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+ fprintf(stderr, "incorrect gamma=%f\n", png_ptr->gamma);
+# endif
+# endif
+#endif
+ }
+ }
+#endif /* PNG_READ_gAMA_SUPPORTED */
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+ if (PNG_OUT_OF_RANGE(info_ptr->int_x_white, 31270, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_y_white, 32900, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_x_red, 64000L, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_y_red, 33000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_x_green, 30000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_y_green, 60000L, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_x_blue, 15000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_y_blue, 6000, 1000))
+ {
+ png_warning(png_ptr,
+ "Ignoring incorrect cHRM value when sRGB is also present");
+ }
+#endif /* PNG_FIXED_POINT_SUPPORTED */
+#endif /* PNG_READ_cHRM_SUPPORTED */
+
+ png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
+}
+#endif /* PNG_READ_sRGB_SUPPORTED */
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+void /* PRIVATE */
+png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+ png_byte compression_type;
+ png_bytep pC;
+ png_charp profile;
+ png_uint_32 skip = 0;
+ png_uint_32 profile_size, profile_length;
+ png_size_t slength, prefix_length, data_length;
+
+ png_debug(1, "in png_handle_iCCP");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before iCCP");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid iCCP after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place iCCP chunk");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
+ {
+ png_warning(png_ptr, "Duplicate iCCP chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "iCCP chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, skip))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00;
+
+ for (profile = png_ptr->chunkdata; *profile; profile++)
+ /* Empty loop to find end of name */ ;
+
+ ++profile;
+
+ /* There should be at least one zero (the compression type byte)
+ * following the separator, and we should be on it
+ */
+ if ( profile >= png_ptr->chunkdata + slength - 1)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "Malformed iCCP chunk");
+ return;
+ }
+
+ /* Compression_type should always be zero */
+ compression_type = *profile++;
+ if (compression_type)
+ {
+ png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
+ compression_type = 0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8
+ wrote nonzero) */
+ }
+
+ prefix_length = profile - png_ptr->chunkdata;
+ png_decompress_chunk(png_ptr, compression_type,
+ slength, prefix_length, &data_length);
+
+ profile_length = data_length - prefix_length;
+
+ if ( prefix_length > data_length || profile_length < 4)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "Profile size field missing from iCCP chunk");
+ return;
+ }
+
+ /* Check the profile_size recorded in the first 32 bits of the ICC profile */
+ pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
+ profile_size = ((*(pC ))<<24) |
+ ((*(pC + 1))<<16) |
+ ((*(pC + 2))<< 8) |
+ ((*(pC + 3)) );
+
+ if (profile_size < profile_length)
+ profile_length = profile_size;
+
+ if (profile_size > profile_length)
+ {
+#ifdef PNG_STDIO_SUPPORTED
+ char umsg[50];
+#endif
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "Ignoring truncated iCCP profile");
+#ifdef PNG_STDIO_SUPPORTED
+
+ png_snprintf(umsg, 50, "declared profile size = %lu",
+ (unsigned long)profile_size);
+ png_warning(png_ptr, umsg);
+ png_snprintf(umsg, 50, "actual profile length = %lu",
+ (unsigned long)profile_length);
+ png_warning(png_ptr, umsg);
+#endif
+ return;
+ }
+
+ png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata,
+ compression_type, png_ptr->chunkdata + prefix_length, profile_length);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+}
+#endif /* PNG_READ_iCCP_SUPPORTED */
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+void /* PRIVATE */
+png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+ png_bytep entry_start;
+ png_sPLT_t new_palette;
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ png_sPLT_entryp pp;
+#endif
+ int data_length, entry_size, i;
+ png_uint_32 skip = 0;
+ png_size_t slength;
+
+ png_debug(1, "in png_handle_sPLT");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for sPLT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sPLT");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sPLT after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "sPLT chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, skip))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00;
+
+ for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start;
+ entry_start++)
+ /* Empty loop to find end of name */ ;
+ ++entry_start;
+
+ /* A sample depth should follow the separator, and we should be on it */
+ if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "malformed sPLT chunk");
+ return;
+ }
+
+ new_palette.depth = *entry_start++;
+ entry_size = (new_palette.depth == 8 ? 6 : 10);
+ data_length = (slength - (entry_start - (png_bytep)png_ptr->chunkdata));
+
+ /* Integrity-check the data length */
+ if (data_length % entry_size)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "sPLT chunk has bad length");
+ return;
+ }
+
+ new_palette.nentries = (png_int_32) ( data_length / entry_size);
+ if ((png_uint_32) new_palette.nentries >
+ (png_uint_32) (PNG_SIZE_MAX / png_sizeof(png_sPLT_entry)))
+ {
+ png_warning(png_ptr, "sPLT chunk too long");
+ return;
+ }
+ new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
+ png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry));
+ if (new_palette.entries == NULL)
+ {
+ png_warning(png_ptr, "sPLT chunk requires too much memory");
+ return;
+ }
+
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ for (i = 0; i < new_palette.nentries; i++)
+ {
+ pp = new_palette.entries + i;
+
+ if (new_palette.depth == 8)
+ {
+ pp->red = *entry_start++;
+ pp->green = *entry_start++;
+ pp->blue = *entry_start++;
+ pp->alpha = *entry_start++;
+ }
+ else
+ {
+ pp->red = png_get_uint_16(entry_start); entry_start += 2;
+ pp->green = png_get_uint_16(entry_start); entry_start += 2;
+ pp->blue = png_get_uint_16(entry_start); entry_start += 2;
+ pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
+ }
+ pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+ }
+#else
+ pp = new_palette.entries;
+ for (i = 0; i < new_palette.nentries; i++)
+ {
+
+ if (new_palette.depth == 8)
+ {
+ pp[i].red = *entry_start++;
+ pp[i].green = *entry_start++;
+ pp[i].blue = *entry_start++;
+ pp[i].alpha = *entry_start++;
+ }
+ else
+ {
+ pp[i].red = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].blue = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
+ }
+ pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+ }
+#endif
+
+ /* Discard all chunk data except the name and stash that */
+ new_palette.name = png_ptr->chunkdata;
+
+ png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_free(png_ptr, new_palette.entries);
+}
+#endif /* PNG_READ_sPLT_SUPPORTED */
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+void /* PRIVATE */
+png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
+
+ png_debug(1, "in png_handle_tRNS");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before tRNS");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid tRNS after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+ {
+ png_warning(png_ptr, "Duplicate tRNS chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ png_byte buf[2];
+
+ if (length != 2)
+ {
+ png_warning(png_ptr, "Incorrect tRNS chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 2);
+ png_ptr->num_trans = 1;
+ png_ptr->trans_color.gray = png_get_uint_16(buf);
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ png_byte buf[6];
+
+ if (length != 6)
+ {
+ png_warning(png_ptr, "Incorrect tRNS chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ png_crc_read(png_ptr, buf, (png_size_t)length);
+ png_ptr->num_trans = 1;
+ png_ptr->trans_color.red = png_get_uint_16(buf);
+ png_ptr->trans_color.green = png_get_uint_16(buf + 2);
+ png_ptr->trans_color.blue = png_get_uint_16(buf + 4);
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (!(png_ptr->mode & PNG_HAVE_PLTE))
+ {
+ /* Should be an error, but we can cope with it. */
+ png_warning(png_ptr, "Missing PLTE before tRNS");
+ }
+ if (length > (png_uint_32)png_ptr->num_palette ||
+ length > PNG_MAX_PALETTE_LENGTH)
+ {
+ png_warning(png_ptr, "Incorrect tRNS chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ if (length == 0)
+ {
+ png_warning(png_ptr, "Zero length tRNS chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ png_crc_read(png_ptr, readbuf, (png_size_t)length);
+ png_ptr->num_trans = (png_uint_16)length;
+ }
+ else
+ {
+ png_warning(png_ptr, "tRNS chunk not allowed with alpha channel");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_ptr->num_trans = 0;
+ return;
+ }
+
+ png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
+ &(png_ptr->trans_color));
+}
+#endif
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+void /* PRIVATE */
+png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_size_t truelen;
+ png_byte buf[6];
+
+ png_debug(1, "in png_handle_bKGD");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before bKGD");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid bKGD after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ !(png_ptr->mode & PNG_HAVE_PLTE))
+ {
+ png_warning(png_ptr, "Missing PLTE before bKGD");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
+ {
+ png_warning(png_ptr, "Duplicate bKGD chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ truelen = 1;
+ else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
+ truelen = 6;
+ else
+ truelen = 2;
+
+ if (length != truelen)
+ {
+ png_warning(png_ptr, "Incorrect bKGD chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, truelen);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ /* We convert the index value into RGB components so that we can allow
+ * arbitrary RGB values for background when we have transparency, and
+ * so it is easy to determine the RGB values of the background color
+ * from the info_ptr struct. */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_ptr->background.index = buf[0];
+ if (info_ptr && info_ptr->num_palette)
+ {
+ if (buf[0] >= info_ptr->num_palette)
+ {
+ png_warning(png_ptr, "Incorrect bKGD chunk index value");
+ return;
+ }
+ png_ptr->background.red =
+ (png_uint_16)png_ptr->palette[buf[0]].red;
+ png_ptr->background.green =
+ (png_uint_16)png_ptr->palette[buf[0]].green;
+ png_ptr->background.blue =
+ (png_uint_16)png_ptr->palette[buf[0]].blue;
+ }
+ }
+ else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
+ {
+ png_ptr->background.red =
+ png_ptr->background.green =
+ png_ptr->background.blue =
+ png_ptr->background.gray = png_get_uint_16(buf);
+ }
+ else
+ {
+ png_ptr->background.red = png_get_uint_16(buf);
+ png_ptr->background.green = png_get_uint_16(buf + 2);
+ png_ptr->background.blue = png_get_uint_16(buf + 4);
+ }
+
+ png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background));
+}
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+void /* PRIVATE */
+png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ unsigned int num, i;
+ png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
+
+ png_debug(1, "in png_handle_hIST");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before hIST");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid hIST after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (!(png_ptr->mode & PNG_HAVE_PLTE))
+ {
+ png_warning(png_ptr, "Missing PLTE before hIST");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
+ {
+ png_warning(png_ptr, "Duplicate hIST chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ num = length / 2 ;
+ if (num != (unsigned int) png_ptr->num_palette || num >
+ (unsigned int) PNG_MAX_PALETTE_LENGTH)
+ {
+ png_warning(png_ptr, "Incorrect hIST chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ for (i = 0; i < num; i++)
+ {
+ png_byte buf[2];
+
+ png_crc_read(png_ptr, buf, 2);
+ readbuf[i] = png_get_uint_16(buf);
+ }
+
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ png_set_hIST(png_ptr, info_ptr, readbuf);
+}
+#endif
+
+#ifdef PNG_READ_pHYs_SUPPORTED
+void /* PRIVATE */
+png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte buf[9];
+ png_uint_32 res_x, res_y;
+ int unit_type;
+
+ png_debug(1, "in png_handle_pHYs");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before pHYs");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid pHYs after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+ {
+ png_warning(png_ptr, "Duplicate pHYs chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 9)
+ {
+ png_warning(png_ptr, "Incorrect pHYs chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 9);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ res_x = png_get_uint_32(buf);
+ res_y = png_get_uint_32(buf + 4);
+ unit_type = buf[8];
+ png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
+}
+#endif
+
+#ifdef PNG_READ_oFFs_SUPPORTED
+void /* PRIVATE */
+png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte buf[9];
+ png_int_32 offset_x, offset_y;
+ int unit_type;
+
+ png_debug(1, "in png_handle_oFFs");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before oFFs");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid oFFs after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+ {
+ png_warning(png_ptr, "Duplicate oFFs chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 9)
+ {
+ png_warning(png_ptr, "Incorrect oFFs chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 9);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ offset_x = png_get_int_32(buf);
+ offset_y = png_get_int_32(buf + 4);
+ unit_type = buf[8];
+ png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
+}
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+/* Read the pCAL chunk (described in the PNG Extensions document) */
+void /* PRIVATE */
+png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_int_32 X0, X1;
+ png_byte type, nparams;
+ png_charp buf, units, endptr;
+ png_charpp params;
+ png_size_t slength;
+ int i;
+
+ png_debug(1, "in png_handle_pCAL");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before pCAL");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid pCAL after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
+ {
+ png_warning(png_ptr, "Duplicate pCAL chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_debug1(2, "Allocating and reading pCAL chunk data (%lu bytes)",
+ length + 1);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "No memory for pCAL purpose");
+ return;
+ }
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
+
+ png_debug(3, "Finding end of pCAL purpose string");
+ for (buf = png_ptr->chunkdata; *buf; buf++)
+ /* Empty loop */ ;
+
+ endptr = png_ptr->chunkdata + slength;
+
+ /* We need to have at least 12 bytes after the purpose string
+ in order to get the parameter information. */
+ if (endptr <= buf + 12)
+ {
+ png_warning(png_ptr, "Invalid pCAL data");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
+ X0 = png_get_int_32((png_bytep)buf+1);
+ X1 = png_get_int_32((png_bytep)buf+5);
+ type = buf[9];
+ nparams = buf[10];
+ units = buf + 11;
+
+ png_debug(3, "Checking pCAL equation type and number of parameters");
+ /* Check that we have the right number of parameters for known
+ equation types. */
+ if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
+ (type == PNG_EQUATION_BASE_E && nparams != 3) ||
+ (type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
+ (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
+ {
+ png_warning(png_ptr, "Invalid pCAL parameters for equation type");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+ else if (type >= PNG_EQUATION_LAST)
+ {
+ png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
+ }
+
+ for (buf = units; *buf; buf++)
+ /* Empty loop to move past the units string. */ ;
+
+ png_debug(3, "Allocating pCAL parameters array");
+ params = (png_charpp)png_malloc_warn(png_ptr,
+ (png_size_t)(nparams * png_sizeof(png_charp)));
+ if (params == NULL)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "No memory for pCAL params");
+ return;
+ }
+
+ /* Get pointers to the start of each parameter string. */
+ for (i = 0; i < (int)nparams; i++)
+ {
+ buf++; /* Skip the null string terminator from previous parameter. */
+
+ png_debug1(3, "Reading pCAL parameter %d", i);
+ for (params[i] = buf; buf <= endptr && *buf != 0x00; buf++)
+ /* Empty loop to move past each parameter string */ ;
+
+ /* Make sure we haven't run out of data yet */
+ if (buf > endptr)
+ {
+ png_warning(png_ptr, "Invalid pCAL data");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_free(png_ptr, params);
+ return;
+ }
+ }
+
+ png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams,
+ units, params);
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_free(png_ptr, params);
+}
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+/* Read the sCAL chunk */
+void /* PRIVATE */
+png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_charp ep;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ double width, height;
+ png_charp vp;
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_charp swidth, sheight;
+#endif
+#endif
+ png_size_t slength;
+
+ png_debug(1, "in png_handle_sCAL");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sCAL");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sCAL after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
+ {
+ png_warning(png_ptr, "Duplicate sCAL chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_debug1(2, "Allocating and reading sCAL chunk data (%lu bytes)",
+ length + 1);
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "Out of memory while processing sCAL chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
+
+ ep = png_ptr->chunkdata + 1; /* Skip unit byte */
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ width = png_strtod(png_ptr, ep, &vp);
+ if (*vp)
+ {
+ png_warning(png_ptr, "malformed width string in sCAL chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ swidth = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
+ if (swidth == NULL)
+ {
+ png_warning(png_ptr, "Out of memory while processing sCAL chunk width");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+ png_memcpy(swidth, ep, png_strlen(ep));
+#endif
+#endif
+
+ for (ep = png_ptr->chunkdata; *ep; ep++)
+ /* Empty loop */ ;
+ ep++;
+
+ if (png_ptr->chunkdata + slength < ep)
+ {
+ png_warning(png_ptr, "Truncated sCAL chunk");
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+ png_free(png_ptr, swidth);
+#endif
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ height = png_strtod(png_ptr, ep, &vp);
+ if (*vp)
+ {
+ png_warning(png_ptr, "malformed height string in sCAL chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ sheight = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
+ if (sheight == NULL)
+ {
+ png_warning(png_ptr, "Out of memory while processing sCAL chunk height");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_free(png_ptr, swidth);
+ return;
+ }
+ png_memcpy(sheight, ep, png_strlen(ep));
+#endif
+#endif
+
+ if (png_ptr->chunkdata + slength < ep
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ || width <= 0. || height <= 0.
+#endif
+ )
+ {
+ png_warning(png_ptr, "Invalid sCAL data");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+ png_free(png_ptr, swidth);
+ png_free(png_ptr, sheight);
+#endif
+ return;
+ }
+
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ png_set_sCAL(png_ptr, info_ptr, png_ptr->chunkdata[0], width, height);
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0], swidth, sheight);
+#endif
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+ png_free(png_ptr, swidth);
+ png_free(png_ptr, sheight);
+#endif
+}
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+void /* PRIVATE */
+png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte buf[7];
+ png_time mod_time;
+
+ png_debug(1, "in png_handle_tIME");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Out of place tIME chunk");
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
+ {
+ png_warning(png_ptr, "Duplicate tIME chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ if (length != 7)
+ {
+ png_warning(png_ptr, "Incorrect tIME chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 7);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ mod_time.second = buf[6];
+ mod_time.minute = buf[5];
+ mod_time.hour = buf[4];
+ mod_time.day = buf[3];
+ mod_time.month = buf[2];
+ mod_time.year = png_get_uint_16(buf);
+
+ png_set_tIME(png_ptr, info_ptr, &mod_time);
+}
+#endif
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_textp text_ptr;
+ png_charp key;
+ png_charp text;
+ png_uint_32 skip = 0;
+ png_size_t slength;
+ int ret;
+
+ png_debug(1, "in png_handle_tEXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for tEXt");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before tEXt");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "tEXt chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "No memory to process text chunk");
+ return;
+ }
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, skip))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ key = png_ptr->chunkdata;
+
+ key[slength] = 0x00;
+
+ for (text = key; *text; text++)
+ /* Empty loop to find end of key */ ;
+
+ if (text != key + slength)
+ text++;
+
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ png_sizeof(png_text));
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr, "Not enough memory to process text chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+ text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
+ text_ptr->key = key;
+#ifdef PNG_iTXt_SUPPORTED
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+ text_ptr->itxt_length = 0;
+#endif
+ text_ptr->text = text;
+ text_ptr->text_length = png_strlen(text);
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_free(png_ptr, text_ptr);
+ if (ret)
+ png_warning(png_ptr, "Insufficient memory to process text chunk");
+}
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_textp text_ptr;
+ png_charp text;
+ int comp_type;
+ int ret;
+ png_size_t slength, prefix_len, data_len;
+
+ png_debug(1, "in png_handle_zTXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for zTXt");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before zTXt");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+ /* We will no doubt have problems with chunks even half this size, but
+ there is no hard and fast rule to tell us where to stop. */
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "zTXt chunk too large to fit in memory");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "Out of memory processing zTXt chunk");
+ return;
+ }
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00;
+
+ for (text = png_ptr->chunkdata; *text; text++)
+ /* Empty loop */ ;
+
+ /* zTXt must have some text after the chunkdataword */
+ if (text >= png_ptr->chunkdata + slength - 2)
+ {
+ png_warning(png_ptr, "Truncated zTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+ else
+ {
+ comp_type = *(++text);
+ if (comp_type != PNG_TEXT_COMPRESSION_zTXt)
+ {
+ png_warning(png_ptr, "Unknown compression type in zTXt chunk");
+ comp_type = PNG_TEXT_COMPRESSION_zTXt;
+ }
+ text++; /* Skip the compression_method byte */
+ }
+ prefix_len = text - png_ptr->chunkdata;
+
+ png_decompress_chunk(png_ptr, comp_type,
+ (png_size_t)length, prefix_len, &data_len);
+
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ png_sizeof(png_text));
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr, "Not enough memory to process zTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+ text_ptr->compression = comp_type;
+ text_ptr->key = png_ptr->chunkdata;
+#ifdef PNG_iTXt_SUPPORTED
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+ text_ptr->itxt_length = 0;
+#endif
+ text_ptr->text = png_ptr->chunkdata + prefix_len;
+ text_ptr->text_length = data_len;
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, text_ptr);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ if (ret)
+ png_error(png_ptr, "Insufficient memory to store zTXt chunk");
+}
+#endif
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_textp text_ptr;
+ png_charp key, lang, text, lang_key;
+ int comp_flag;
+ int comp_type = 0;
+ int ret;
+ png_size_t slength, prefix_len, data_len;
+
+ png_debug(1, "in png_handle_iTXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for iTXt");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before iTXt");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+ /* We will no doubt have problems with chunks even half this size, but
+ there is no hard and fast rule to tell us where to stop. */
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "iTXt chunk too large to fit in memory");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "No memory to process iTXt chunk");
+ return;
+ }
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00;
+
+ for (lang = png_ptr->chunkdata; *lang; lang++)
+ /* Empty loop */ ;
+ lang++; /* Skip NUL separator */
+
+ /* iTXt must have a language tag (possibly empty), two compression bytes,
+ * translated keyword (possibly empty), and possibly some text after the
+ * keyword
+ */
+
+ if (lang >= png_ptr->chunkdata + slength - 3)
+ {
+ png_warning(png_ptr, "Truncated iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+ else
+ {
+ comp_flag = *lang++;
+ comp_type = *lang++;
+ }
+
+ for (lang_key = lang; *lang_key; lang_key++)
+ /* Empty loop */ ;
+ lang_key++; /* Skip NUL separator */
+
+ if (lang_key >= png_ptr->chunkdata + slength)
+ {
+ png_warning(png_ptr, "Truncated iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ for (text = lang_key; *text; text++)
+ /* Empty loop */ ;
+ text++; /* Skip NUL separator */
+ if (text >= png_ptr->chunkdata + slength)
+ {
+ png_warning(png_ptr, "Malformed iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ prefix_len = text - png_ptr->chunkdata;
+
+ key=png_ptr->chunkdata;
+ if (comp_flag)
+ png_decompress_chunk(png_ptr, comp_type,
+ (size_t)length, prefix_len, &data_len);
+ else
+ data_len = png_strlen(png_ptr->chunkdata + prefix_len);
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ png_sizeof(png_text));
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr, "Not enough memory to process iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+ text_ptr->compression = (int)comp_flag + 1;
+ text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key);
+ text_ptr->lang = png_ptr->chunkdata + (lang - key);
+ text_ptr->itxt_length = data_len;
+ text_ptr->text_length = 0;
+ text_ptr->key = png_ptr->chunkdata;
+ text_ptr->text = png_ptr->chunkdata + prefix_len;
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, text_ptr);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ if (ret)
+ png_error(png_ptr, "Insufficient memory to store iTXt chunk");
+}
+#endif
+
+/* This function is called when we haven't found a handler for a
+ chunk. If there isn't a problem with the chunk itself (ie bad
+ chunk name, CRC, or a critical chunk), the chunk is silently ignored
+ -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
+ case it will be saved away to be written out later. */
+void /* PRIVATE */
+png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_uint_32 skip = 0;
+
+ png_debug(1, "in png_handle_unknown");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for unknown chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ PNG_IDAT;
+ if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* Not an IDAT */
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ }
+
+ if (!(png_ptr->chunk_name[0] & 0x20))
+ {
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ && png_ptr->read_user_chunk_fn == NULL
+#endif
+ )
+#endif
+ png_chunk_error(png_ptr, "unknown critical chunk");
+ }
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+ if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ || (png_ptr->read_user_chunk_fn != NULL)
+#endif
+ )
+ {
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "unknown chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+ png_memcpy((png_charp)png_ptr->unknown_chunk.name,
+ (png_charp)png_ptr->chunk_name,
+ png_sizeof(png_ptr->unknown_chunk.name));
+ png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1]
+ = '\0';
+ png_ptr->unknown_chunk.size = (png_size_t)length;
+ if (length == 0)
+ png_ptr->unknown_chunk.data = NULL;
+ else
+ {
+ png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
+ png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
+ }
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ if (png_ptr->read_user_chunk_fn != NULL)
+ {
+ /* Callback to user unknown chunk handler */
+ int ret;
+ ret = (*(png_ptr->read_user_chunk_fn))
+ (png_ptr, &png_ptr->unknown_chunk);
+ if (ret < 0)
+ png_chunk_error(png_ptr, "error in user chunk");
+ if (ret == 0)
+ {
+ if (!(png_ptr->chunk_name[0] & 0x20))
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS)
+#endif
+ png_chunk_error(png_ptr, "unknown critical chunk");
+ png_set_unknown_chunks(png_ptr, info_ptr,
+ &png_ptr->unknown_chunk, 1);
+ }
+ }
+ else
+#endif
+ png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+ }
+ else
+#endif
+ skip = length;
+
+ png_crc_finish(png_ptr, skip);
+
+#ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+ info_ptr = info_ptr; /* Quiet compiler warnings about unused info_ptr */
+#endif
+}
+
+/* This function is called to verify that a chunk name is valid.
+ This function can't have the "critical chunk check" incorporated
+ into it, since in the future we will need to be able to call user
+ functions to handle unknown critical chunks after we check that
+ the chunk name itself is valid. */
+
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+
+void /* PRIVATE */
+png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
+{
+ png_debug(1, "in png_check_chunk_name");
+ if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) ||
+ isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3]))
+ {
+ png_chunk_error(png_ptr, "invalid chunk type");
+ }
+}
+
+/* Combines the row recently read in with the existing pixels in the
+ row. This routine takes care of alpha and transparency if requested.
+ This routine also handles the two methods of progressive display
+ of interlaced images, depending on the mask value.
+ The mask value describes which pixels are to be combined with
+ the row. The pattern always repeats every 8 pixels, so just 8
+ bits are needed. A one indicates the pixel is to be combined,
+ a zero indicates the pixel is to be skipped. This is in addition
+ to any alpha or transparency value associated with the pixel. If
+ you want all pixels to be combined, pass 0xff (255) in mask. */
+
+void /* PRIVATE */
+png_combine_row(png_structp png_ptr, png_bytep row, int mask)
+{
+ png_debug(1, "in png_combine_row");
+ if (mask == 0xff)
+ {
+ png_memcpy(row, png_ptr->row_buf + 1,
+ PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width));
+ }
+ else
+ {
+ switch (png_ptr->row_info.pixel_depth)
+ {
+ case 1:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ int s_inc, s_start, s_end;
+ int m = 0x80;
+ int shift;
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 7;
+ s_inc = 1;
+ }
+ else
+#endif
+ {
+ s_start = 7;
+ s_end = 0;
+ s_inc = -1;
+ }
+
+ shift = s_start;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ int value;
+
+ value = (*sp >> shift) & 0x01;
+ *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+ else
+ shift += s_inc;
+
+ if (m == 1)
+ m = 0x80;
+ else
+ m >>= 1;
+ }
+ break;
+ }
+ case 2:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ int s_start, s_end, s_inc;
+ int m = 0x80;
+ int shift;
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+ int value;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 6;
+ s_inc = 2;
+ }
+ else
+#endif
+ {
+ s_start = 6;
+ s_end = 0;
+ s_inc = -2;
+ }
+
+ shift = s_start;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ value = (*sp >> shift) & 0x03;
+ *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+ else
+ shift += s_inc;
+ if (m == 1)
+ m = 0x80;
+ else
+ m >>= 1;
+ }
+ break;
+ }
+ case 4:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ int s_start, s_end, s_inc;
+ int m = 0x80;
+ int shift;
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+ int value;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 4;
+ s_inc = 4;
+ }
+ else
+#endif
+ {
+ s_start = 4;
+ s_end = 0;
+ s_inc = -4;
+ }
+ shift = s_start;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ value = (*sp >> shift) & 0xf;
+ *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+ else
+ shift += s_inc;
+ if (m == 1)
+ m = 0x80;
+ else
+ m >>= 1;
+ }
+ break;
+ }
+ default:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+ png_byte m = 0x80;
+
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ png_memcpy(dp, sp, pixel_bytes);
+ }
+
+ sp += pixel_bytes;
+ dp += pixel_bytes;
+
+ if (m == 1)
+ m = 0x80;
+ else
+ m >>= 1;
+ }
+ break;
+ }
+ }
+ }
+}
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+/* OLD pre-1.0.9 interface:
+void png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
+ png_uint_32 transformations)
+ */
+void /* PRIVATE */
+png_do_read_interlace(png_structp png_ptr)
+{
+ png_row_infop row_info = &(png_ptr->row_info);
+ png_bytep row = png_ptr->row_buf + 1;
+ int pass = png_ptr->pass;
+ png_uint_32 transformations = png_ptr->transformations;
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+ /* Offset to next interlace block */
+ PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ png_debug(1, "in png_do_read_interlace");
+ if (row != NULL && row_info != NULL)
+ {
+ png_uint_32 final_width;
+
+ final_width = row_info->width * png_pass_inc[pass];
+
+ switch (row_info->pixel_depth)
+ {
+ case 1:
+ {
+ png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
+ png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ int jstop = png_pass_inc[pass];
+ png_byte v;
+ png_uint_32 i;
+ int j;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (transformations & PNG_PACKSWAP)
+ {
+ sshift = (int)((row_info->width + 7) & 0x07);
+ dshift = (int)((final_width + 7) & 0x07);
+ s_start = 7;
+ s_end = 0;
+ s_inc = -1;
+ }
+ else
+#endif
+ {
+ sshift = 7 - (int)((row_info->width + 7) & 0x07);
+ dshift = 7 - (int)((final_width + 7) & 0x07);
+ s_start = 0;
+ s_end = 7;
+ s_inc = 1;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ v = (png_byte)((*sp >> sshift) & 0x01);
+ for (j = 0; j < jstop; j++)
+ {
+ *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+ else
+ dshift += s_inc;
+ }
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+ case 2:
+ {
+ png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
+ png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ int jstop = png_pass_inc[pass];
+ png_uint_32 i;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (transformations & PNG_PACKSWAP)
+ {
+ sshift = (int)(((row_info->width + 3) & 0x03) << 1);
+ dshift = (int)(((final_width + 3) & 0x03) << 1);
+ s_start = 6;
+ s_end = 0;
+ s_inc = -2;
+ }
+ else
+#endif
+ {
+ sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
+ dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
+ s_start = 0;
+ s_end = 6;
+ s_inc = 2;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v;
+ int j;
+
+ v = (png_byte)((*sp >> sshift) & 0x03);
+ for (j = 0; j < jstop; j++)
+ {
+ *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+ else
+ dshift += s_inc;
+ }
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+ case 4:
+ {
+ png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
+ png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ png_uint_32 i;
+ int jstop = png_pass_inc[pass];
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (transformations & PNG_PACKSWAP)
+ {
+ sshift = (int)(((row_info->width + 1) & 0x01) << 2);
+ dshift = (int)(((final_width + 1) & 0x01) << 2);
+ s_start = 4;
+ s_end = 0;
+ s_inc = -4;
+ }
+ else
+#endif
+ {
+ sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
+ dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
+ s_start = 0;
+ s_end = 4;
+ s_inc = 4;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v = (png_byte)((*sp >> sshift) & 0xf);
+ int j;
+
+ for (j = 0; j < jstop; j++)
+ {
+ *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+ else
+ dshift += s_inc;
+ }
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+ default:
+ {
+ png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
+ png_bytep sp = row + (png_size_t)(row_info->width - 1)
+ * pixel_bytes;
+ png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
+
+ int jstop = png_pass_inc[pass];
+ png_uint_32 i;
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v[8];
+ int j;
+
+ png_memcpy(v, sp, pixel_bytes);
+ for (j = 0; j < jstop; j++)
+ {
+ png_memcpy(dp, v, pixel_bytes);
+ dp -= pixel_bytes;
+ }
+ sp -= pixel_bytes;
+ }
+ break;
+ }
+ }
+ row_info->width = final_width;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
+ }
+#ifndef PNG_READ_PACKSWAP_SUPPORTED
+ transformations = transformations; /* Silence compiler warning */
+#endif
+}
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+
+void /* PRIVATE */
+png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
+ png_bytep prev_row, int filter)
+{
+ png_debug(1, "in png_read_filter_row");
+ png_debug2(2, "row = %lu, filter = %d", png_ptr->row_number, filter);
+ switch (filter)
+ {
+ case PNG_FILTER_VALUE_NONE:
+ break;
+ case PNG_FILTER_VALUE_SUB:
+ {
+ png_uint_32 i;
+ png_uint_32 istop = row_info->rowbytes;
+ png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+ png_bytep rp = row + bpp;
+ png_bytep lp = row;
+
+ for (i = bpp; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
+ rp++;
+ }
+ break;
+ }
+ case PNG_FILTER_VALUE_UP:
+ {
+ png_uint_32 i;
+ png_uint_32 istop = row_info->rowbytes;
+ png_bytep rp = row;
+ png_bytep pp = prev_row;
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+ rp++;
+ }
+ break;
+ }
+ case PNG_FILTER_VALUE_AVG:
+ {
+ png_uint_32 i;
+ png_bytep rp = row;
+ png_bytep pp = prev_row;
+ png_bytep lp = row;
+ png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+ png_uint_32 istop = row_info->rowbytes - bpp;
+
+ for (i = 0; i < bpp; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ ((int)(*pp++) / 2 )) & 0xff);
+ rp++;
+ }
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ (int)(*pp++ + *lp++) / 2 ) & 0xff);
+ rp++;
+ }
+ break;
+ }
+ case PNG_FILTER_VALUE_PAETH:
+ {
+ png_uint_32 i;
+ png_bytep rp = row;
+ png_bytep pp = prev_row;
+ png_bytep lp = row;
+ png_bytep cp = prev_row;
+ png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+ png_uint_32 istop=row_info->rowbytes - bpp;
+
+ for (i = 0; i < bpp; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+ rp++;
+ }
+
+ for (i = 0; i < istop; i++) /* Use leftover rp,pp */
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ a = *lp++;
+ b = *pp++;
+ c = *cp++;
+
+ p = b - c;
+ pc = a - c;
+
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+ /*
+ if (pa <= pb && pa <= pc)
+ p = a;
+ else if (pb <= pc)
+ p = b;
+ else
+ p = c;
+ */
+
+ p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c;
+
+ *rp = (png_byte)(((int)(*rp) + p) & 0xff);
+ rp++;
+ }
+ break;
+ }
+ default:
+ png_warning(png_ptr, "Ignoring bad adaptive filter type");
+ *row = 0;
+ break;
+ }
+}
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+void /* PRIVATE */
+png_read_finish_row(png_structp png_ptr)
+{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+
+ png_debug(1, "in png_read_finish_row");
+ png_ptr->row_number++;
+ if (png_ptr->row_number < png_ptr->num_rows)
+ return;
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if (png_ptr->interlaced)
+ {
+ png_ptr->row_number = 0;
+ png_memset(png_ptr->prev_row, 0,
+ png_ptr->rowbytes + 1);
+ do
+ {
+ png_ptr->pass++;
+ if (png_ptr->pass >= 7)
+ break;
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+
+ if (!(png_ptr->transformations & PNG_INTERLACE))
+ {
+ png_ptr->num_rows = (png_ptr->height +
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
+ if (!(png_ptr->num_rows))
+ continue;
+ }
+ else /* if (png_ptr->transformations & PNG_INTERLACE) */
+ break;
+ } while (png_ptr->iwidth == 0);
+
+ if (png_ptr->pass < 7)
+ return;
+ }
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+ {
+ PNG_IDAT;
+ char extra;
+ int ret;
+
+ png_ptr->zstream.next_out = (Byte *)&extra;
+ png_ptr->zstream.avail_out = (uInt)1;
+ for (;;)
+ {
+ if (!(png_ptr->zstream.avail_in))
+ {
+ while (!png_ptr->idat_size)
+ {
+ png_byte chunk_length[4];
+
+ png_crc_finish(png_ptr, 0);
+
+ png_read_data(png_ptr, chunk_length, 4);
+ png_ptr->idat_size = png_get_uint_31(png_ptr, chunk_length);
+ png_reset_crc(png_ptr);
+ png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+ if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ png_error(png_ptr, "Not enough image data");
+
+ }
+ png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
+ png_ptr->zstream.next_in = png_ptr->zbuf;
+ if (png_ptr->zbuf_size > png_ptr->idat_size)
+ png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
+ png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in);
+ png_ptr->idat_size -= png_ptr->zstream.avail_in;
+ }
+ ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+ if (ret == Z_STREAM_END)
+ {
+ if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in ||
+ png_ptr->idat_size)
+ png_warning(png_ptr, "Extra compressed data");
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ break;
+ }
+ if (ret != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
+ "Decompression Error");
+
+ if (!(png_ptr->zstream.avail_out))
+ {
+ png_warning(png_ptr, "Extra compressed data");
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ break;
+ }
+
+ }
+ png_ptr->zstream.avail_out = 0;
+ }
+
+ if (png_ptr->idat_size || png_ptr->zstream.avail_in)
+ png_warning(png_ptr, "Extra compression data");
+
+ inflateReset(&png_ptr->zstream);
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+
+void /* PRIVATE */
+png_read_start_row(png_structp png_ptr)
+{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
+ int max_pixel_depth;
+ png_size_t row_bytes;
+
+ png_debug(1, "in png_read_start_row");
+ png_ptr->zstream.avail_in = 0;
+ png_init_read_transformations(png_ptr);
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if (png_ptr->interlaced)
+ {
+ if (!(png_ptr->transformations & PNG_INTERLACE))
+ png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+ png_pass_ystart[0]) / png_pass_yinc[0];
+ else
+ png_ptr->num_rows = png_ptr->height;
+
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+ }
+ else
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+ {
+ png_ptr->num_rows = png_ptr->height;
+ png_ptr->iwidth = png_ptr->width;
+ }
+ max_pixel_depth = png_ptr->pixel_depth;
+
+#ifdef PNG_READ_PACK_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8)
+ max_pixel_depth = 8;
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ if (png_ptr->transformations & PNG_EXPAND)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (png_ptr->num_trans)
+ max_pixel_depth = 32;
+ else
+ max_pixel_depth = 24;
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (max_pixel_depth < 8)
+ max_pixel_depth = 8;
+ if (png_ptr->num_trans)
+ max_pixel_depth *= 2;
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if (png_ptr->num_trans)
+ {
+ max_pixel_depth *= 4;
+ max_pixel_depth /= 3;
+ }
+ }
+ }
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+ if (png_ptr->transformations & (PNG_FILLER))
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ max_pixel_depth = 32;
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (max_pixel_depth <= 8)
+ max_pixel_depth = 16;
+ else
+ max_pixel_depth = 32;
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if (max_pixel_depth <= 32)
+ max_pixel_depth = 32;
+ else
+ max_pixel_depth = 64;
+ }
+ }
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ if (png_ptr->transformations & PNG_GRAY_TO_RGB)
+ {
+ if (
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
+#endif
+#ifdef PNG_READ_FILLER_SUPPORTED
+ (png_ptr->transformations & (PNG_FILLER)) ||
+#endif
+ png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (max_pixel_depth <= 16)
+ max_pixel_depth = 32;
+ else
+ max_pixel_depth = 64;
+ }
+ else
+ {
+ if (max_pixel_depth <= 8)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 32;
+ else
+ max_pixel_depth = 24;
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 64;
+ else
+ max_pixel_depth = 48;
+ }
+ }
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
+defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+ if (png_ptr->transformations & PNG_USER_TRANSFORM)
+ {
+ int user_pixel_depth = png_ptr->user_transform_depth*
+ png_ptr->user_transform_channels;
+ if (user_pixel_depth > max_pixel_depth)
+ max_pixel_depth=user_pixel_depth;
+ }
+#endif
+
+ /* Align the width on the next larger 8 pixels. Mainly used
+ * for interlacing
+ */
+ row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
+ /* Calculate the maximum bytes needed, adding a byte and a pixel
+ * for safety's sake
+ */
+ row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
+ 1 + ((max_pixel_depth + 7) >> 3);
+#ifdef PNG_MAX_MALLOC_64K
+ if (row_bytes > (png_uint_32)65536L)
+ png_error(png_ptr, "This image requires a row greater than 64KB");
+#endif
+
+ if (row_bytes + 48 > png_ptr->old_big_row_buf_size)
+ {
+ png_free(png_ptr, png_ptr->big_row_buf);
+ if (png_ptr->interlaced)
+ png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr,
+ row_bytes + 48);
+ else
+ png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr,
+ row_bytes + 48);
+ png_ptr->old_big_row_buf_size = row_bytes + 48;
+
+#ifdef PNG_ALIGNED_MEMORY_SUPPORTED
+ /* Use 16-byte aligned memory for row_buf with at least 16 bytes
+ * of padding before and after row_buf.
+ */
+ png_ptr->row_buf = png_ptr->big_row_buf + 32
+ - (((png_alloc_size_t)&(png_ptr->big_row_buf[0]) + 15) % 16);
+ png_ptr->old_big_row_buf_size = row_bytes + 48;
+#else
+ /* Use 32 bytes of padding before and 16 bytes after row_buf. */
+ png_ptr->row_buf = png_ptr->big_row_buf + 32;
+#endif
+ png_ptr->old_big_row_buf_size = row_bytes + 48;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L)
+ png_error(png_ptr, "This image requires a row greater than 64KB");
+#endif
+ if ((png_uint_32)png_ptr->rowbytes > (png_uint_32)(PNG_SIZE_MAX - 1))
+ png_error(png_ptr, "Row has too many bytes to allocate in memory");
+
+ if (png_ptr->rowbytes + 1 > png_ptr->old_prev_row_size)
+ {
+ png_free(png_ptr, png_ptr->prev_row);
+ png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)(
+ png_ptr->rowbytes + 1));
+ png_ptr->old_prev_row_size = png_ptr->rowbytes + 1;
+ }
+
+ png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+ png_debug1(3, "width = %lu,", png_ptr->width);
+ png_debug1(3, "height = %lu,", png_ptr->height);
+ png_debug1(3, "iwidth = %lu,", png_ptr->iwidth);
+ png_debug1(3, "num_rows = %lu,", png_ptr->num_rows);
+ png_debug1(3, "rowbytes = %lu,", png_ptr->rowbytes);
+ png_debug1(3, "irowbytes = %lu",
+ PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1);
+
+ png_ptr->flags |= PNG_FLAG_ROW_INIT;
+}
+#endif /* PNG_READ_SUPPORTED */
--- /dev/null
+
+/* pngset.c - storage of image information into info struct
+ *
+ * Last changed in libpng 1.4.1 [February 25, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * The functions here are used during reads to store data from the file
+ * into the info struct, and during writes to store application data
+ * into the info struct for writing into the file. This abstracts the
+ * info struct and allows us to change the structure in the future.
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#include "pngpriv.h"
+
+#ifdef PNG_bKGD_SUPPORTED
+void PNGAPI
+png_set_bKGD(png_structp png_ptr, png_infop info_ptr, png_color_16p background)
+{
+ png_debug1(1, "in %s storage function", "bKGD");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_memcpy(&(info_ptr->background), background, png_sizeof(png_color_16));
+ info_ptr->valid |= PNG_INFO_bKGD;
+}
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_cHRM(png_structp png_ptr, png_infop info_ptr,
+ double white_x, double white_y, double red_x, double red_y,
+ double green_x, double green_y, double blue_x, double blue_y)
+{
+ png_debug1(1, "in %s storage function", "cHRM");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->x_white = (float)white_x;
+ info_ptr->y_white = (float)white_y;
+ info_ptr->x_red = (float)red_x;
+ info_ptr->y_red = (float)red_y;
+ info_ptr->x_green = (float)green_x;
+ info_ptr->y_green = (float)green_y;
+ info_ptr->x_blue = (float)blue_x;
+ info_ptr->y_blue = (float)blue_y;
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ info_ptr->int_x_white = (png_fixed_point)(white_x*100000.+0.5);
+ info_ptr->int_y_white = (png_fixed_point)(white_y*100000.+0.5);
+ info_ptr->int_x_red = (png_fixed_point)( red_x*100000.+0.5);
+ info_ptr->int_y_red = (png_fixed_point)( red_y*100000.+0.5);
+ info_ptr->int_x_green = (png_fixed_point)(green_x*100000.+0.5);
+ info_ptr->int_y_green = (png_fixed_point)(green_y*100000.+0.5);
+ info_ptr->int_x_blue = (png_fixed_point)( blue_x*100000.+0.5);
+ info_ptr->int_y_blue = (png_fixed_point)( blue_y*100000.+0.5);
+#endif
+ info_ptr->valid |= PNG_INFO_cHRM;
+}
+#endif /* PNG_FLOATING_POINT_SUPPORTED */
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_cHRM_fixed(png_structp png_ptr, png_infop info_ptr,
+ png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
+ png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
+ png_fixed_point blue_x, png_fixed_point blue_y)
+{
+ png_debug1(1, "in %s storage function", "cHRM fixed");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+#ifdef PNG_CHECK_cHRM_SUPPORTED
+ if (png_check_cHRM_fixed(png_ptr,
+ white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y))
+#endif
+ {
+ info_ptr->int_x_white = white_x;
+ info_ptr->int_y_white = white_y;
+ info_ptr->int_x_red = red_x;
+ info_ptr->int_y_red = red_y;
+ info_ptr->int_x_green = green_x;
+ info_ptr->int_y_green = green_y;
+ info_ptr->int_x_blue = blue_x;
+ info_ptr->int_y_blue = blue_y;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ info_ptr->x_white = (float)(white_x/100000.);
+ info_ptr->y_white = (float)(white_y/100000.);
+ info_ptr->x_red = (float)( red_x/100000.);
+ info_ptr->y_red = (float)( red_y/100000.);
+ info_ptr->x_green = (float)(green_x/100000.);
+ info_ptr->y_green = (float)(green_y/100000.);
+ info_ptr->x_blue = (float)( blue_x/100000.);
+ info_ptr->y_blue = (float)( blue_y/100000.);
+#endif
+ info_ptr->valid |= PNG_INFO_cHRM;
+ }
+}
+#endif /* PNG_FIXED_POINT_SUPPORTED */
+#endif /* PNG_cHRM_SUPPORTED */
+
+#ifdef PNG_gAMA_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_gAMA(png_structp png_ptr, png_infop info_ptr, double file_gamma)
+{
+ double png_gamma;
+
+ png_debug1(1, "in %s storage function", "gAMA");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* Check for overflow */
+ if (file_gamma > 21474.83)
+ {
+ png_warning(png_ptr, "Limiting gamma to 21474.83");
+ png_gamma=21474.83;
+ }
+ else
+ png_gamma = file_gamma;
+ info_ptr->gamma = (float)png_gamma;
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ info_ptr->int_gamma = (int)(png_gamma*100000.+.5);
+#endif
+ info_ptr->valid |= PNG_INFO_gAMA;
+ if (png_gamma == 0.0)
+ png_warning(png_ptr, "Setting gamma=0");
+}
+#endif
+void PNGAPI
+png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point
+ int_gamma)
+{
+ png_fixed_point png_gamma;
+
+ png_debug1(1, "in %s storage function", "gAMA");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (int_gamma > (png_fixed_point)PNG_UINT_31_MAX)
+ {
+ png_warning(png_ptr, "Limiting gamma to 21474.83");
+ png_gamma=PNG_UINT_31_MAX;
+ }
+ else
+ {
+ if (int_gamma < 0)
+ {
+ png_warning(png_ptr, "Setting negative gamma to zero");
+ png_gamma = 0;
+ }
+ else
+ png_gamma = int_gamma;
+ }
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ info_ptr->gamma = (float)(png_gamma/100000.);
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ info_ptr->int_gamma = png_gamma;
+#endif
+ info_ptr->valid |= PNG_INFO_gAMA;
+ if (png_gamma == 0)
+ png_warning(png_ptr, "Setting gamma=0");
+}
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+void PNGAPI
+png_set_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p hist)
+{
+ int i;
+
+ png_debug1(1, "in %s storage function", "hIST");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (info_ptr->num_palette == 0 || info_ptr->num_palette
+ > PNG_MAX_PALETTE_LENGTH)
+ {
+ png_warning(png_ptr,
+ "Invalid palette size, hIST allocation skipped");
+ return;
+ }
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0);
+ /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in
+ * version 1.2.1
+ */
+ png_ptr->hist = (png_uint_16p)png_malloc_warn(png_ptr,
+ PNG_MAX_PALETTE_LENGTH * png_sizeof(png_uint_16));
+ if (png_ptr->hist == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for hIST chunk data");
+ return;
+ }
+
+ for (i = 0; i < info_ptr->num_palette; i++)
+ png_ptr->hist[i] = hist[i];
+ info_ptr->hist = png_ptr->hist;
+ info_ptr->valid |= PNG_INFO_hIST;
+
+ info_ptr->free_me |= PNG_FREE_HIST;
+}
+#endif
+
+void PNGAPI
+png_set_IHDR(png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_type, int compression_type,
+ int filter_type)
+{
+ png_debug1(1, "in %s storage function", "IHDR");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->width = width;
+ info_ptr->height = height;
+ info_ptr->bit_depth = (png_byte)bit_depth;
+ info_ptr->color_type = (png_byte)color_type;
+ info_ptr->compression_type = (png_byte)compression_type;
+ info_ptr->filter_type = (png_byte)filter_type;
+ info_ptr->interlace_type = (png_byte)interlace_type;
+
+ png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+ info_ptr->compression_type, info_ptr->filter_type);
+
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ info_ptr->channels = 1;
+ else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
+ info_ptr->channels = 3;
+ else
+ info_ptr->channels = 1;
+ if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
+ info_ptr->channels++;
+ info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
+
+ /* Check for potential overflow */
+ if (width > (PNG_UINT_32_MAX
+ >> 3) /* 8-byte RGBA pixels */
+ - 64 /* bigrowbuf hack */
+ - 1 /* filter byte */
+ - 7*8 /* rounding of width to multiple of 8 pixels */
+ - 8) /* extra max_pixel_depth pad */
+ info_ptr->rowbytes = 0;
+ else
+ info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
+}
+
+#ifdef PNG_oFFs_SUPPORTED
+void PNGAPI
+png_set_oFFs(png_structp png_ptr, png_infop info_ptr,
+ png_int_32 offset_x, png_int_32 offset_y, int unit_type)
+{
+ png_debug1(1, "in %s storage function", "oFFs");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->x_offset = offset_x;
+ info_ptr->y_offset = offset_y;
+ info_ptr->offset_unit_type = (png_byte)unit_type;
+ info_ptr->valid |= PNG_INFO_oFFs;
+}
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+void PNGAPI
+png_set_pCAL(png_structp png_ptr, png_infop info_ptr,
+ png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
+ png_charp units, png_charpp params)
+{
+ png_size_t length;
+ int i;
+
+ png_debug1(1, "in %s storage function", "pCAL");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ length = png_strlen(purpose) + 1;
+ png_debug1(3, "allocating purpose for info (%lu bytes)",
+ (unsigned long)length);
+ info_ptr->pcal_purpose = (png_charp)png_malloc_warn(png_ptr, length);
+ if (info_ptr->pcal_purpose == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for pCAL purpose");
+ return;
+ }
+ png_memcpy(info_ptr->pcal_purpose, purpose, length);
+
+ png_debug(3, "storing X0, X1, type, and nparams in info");
+ info_ptr->pcal_X0 = X0;
+ info_ptr->pcal_X1 = X1;
+ info_ptr->pcal_type = (png_byte)type;
+ info_ptr->pcal_nparams = (png_byte)nparams;
+
+ length = png_strlen(units) + 1;
+ png_debug1(3, "allocating units for info (%lu bytes)",
+ (unsigned long)length);
+ info_ptr->pcal_units = (png_charp)png_malloc_warn(png_ptr, length);
+ if (info_ptr->pcal_units == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for pCAL units");
+ return;
+ }
+ png_memcpy(info_ptr->pcal_units, units, length);
+
+ info_ptr->pcal_params = (png_charpp)png_malloc_warn(png_ptr,
+ (png_size_t)((nparams + 1) * png_sizeof(png_charp)));
+ if (info_ptr->pcal_params == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for pCAL params");
+ return;
+ }
+
+ png_memset(info_ptr->pcal_params, 0, (nparams + 1) * png_sizeof(png_charp));
+
+ for (i = 0; i < nparams; i++)
+ {
+ length = png_strlen(params[i]) + 1;
+ png_debug2(3, "allocating parameter %d for info (%lu bytes)", i,
+ (unsigned long)length);
+ info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length);
+ if (info_ptr->pcal_params[i] == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for pCAL parameter");
+ return;
+ }
+ png_memcpy(info_ptr->pcal_params[i], params[i], length);
+ }
+
+ info_ptr->valid |= PNG_INFO_pCAL;
+ info_ptr->free_me |= PNG_FREE_PCAL;
+}
+#endif
+
+#if defined(PNG_READ_sCAL_SUPPORTED) || defined(PNG_WRITE_sCAL_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL(png_structp png_ptr, png_infop info_ptr,
+ int unit, double width, double height)
+{
+ png_debug1(1, "in %s storage function", "sCAL");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->scal_unit = (png_byte)unit;
+ info_ptr->scal_pixel_width = width;
+ info_ptr->scal_pixel_height = height;
+
+ info_ptr->valid |= PNG_INFO_sCAL;
+}
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr,
+ int unit, png_charp swidth, png_charp sheight)
+{
+ png_size_t length;
+
+ png_debug1(1, "in %s storage function", "sCAL");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->scal_unit = (png_byte)unit;
+
+ length = png_strlen(swidth) + 1;
+ png_debug1(3, "allocating unit for info (%u bytes)",
+ (unsigned int)length);
+ info_ptr->scal_s_width = (png_charp)png_malloc_warn(png_ptr, length);
+ if (info_ptr->scal_s_width == NULL)
+ {
+ png_warning(png_ptr,
+ "Memory allocation failed while processing sCAL");
+ return;
+ }
+ png_memcpy(info_ptr->scal_s_width, swidth, length);
+
+ length = png_strlen(sheight) + 1;
+ png_debug1(3, "allocating unit for info (%u bytes)",
+ (unsigned int)length);
+ info_ptr->scal_s_height = (png_charp)png_malloc_warn(png_ptr, length);
+ if (info_ptr->scal_s_height == NULL)
+ {
+ png_free (png_ptr, info_ptr->scal_s_width);
+ info_ptr->scal_s_width = NULL;
+ png_warning(png_ptr,
+ "Memory allocation failed while processing sCAL");
+ return;
+ }
+ png_memcpy(info_ptr->scal_s_height, sheight, length);
+ info_ptr->valid |= PNG_INFO_sCAL;
+ info_ptr->free_me |= PNG_FREE_SCAL;
+}
+#endif
+#endif
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+void PNGAPI
+png_set_pHYs(png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 res_x, png_uint_32 res_y, int unit_type)
+{
+ png_debug1(1, "in %s storage function", "pHYs");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->x_pixels_per_unit = res_x;
+ info_ptr->y_pixels_per_unit = res_y;
+ info_ptr->phys_unit_type = (png_byte)unit_type;
+ info_ptr->valid |= PNG_INFO_pHYs;
+}
+#endif
+
+void PNGAPI
+png_set_PLTE(png_structp png_ptr, png_infop info_ptr,
+ png_colorp palette, int num_palette)
+{
+
+ png_debug1(1, "in %s storage function", "PLTE");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (num_palette < 0 || num_palette > PNG_MAX_PALETTE_LENGTH)
+ {
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ png_error(png_ptr, "Invalid palette length");
+ else
+ {
+ png_warning(png_ptr, "Invalid palette length");
+ return;
+ }
+ }
+
+ /* It may not actually be necessary to set png_ptr->palette here;
+ * we do it for backward compatibility with the way the png_handle_tRNS
+ * function used to do the allocation.
+ */
+ png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);
+
+ /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
+ * of num_palette entries, in case of an invalid PNG file that has
+ * too-large sample values.
+ */
+ png_ptr->palette = (png_colorp)png_calloc(png_ptr,
+ PNG_MAX_PALETTE_LENGTH * png_sizeof(png_color));
+ png_memcpy(png_ptr->palette, palette, num_palette * png_sizeof(png_color));
+ info_ptr->palette = png_ptr->palette;
+ info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
+
+ info_ptr->free_me |= PNG_FREE_PLTE;
+
+ info_ptr->valid |= PNG_INFO_PLTE;
+}
+
+#ifdef PNG_sBIT_SUPPORTED
+void PNGAPI
+png_set_sBIT(png_structp png_ptr, png_infop info_ptr,
+ png_color_8p sig_bit)
+{
+ png_debug1(1, "in %s storage function", "sBIT");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_memcpy(&(info_ptr->sig_bit), sig_bit, png_sizeof(png_color_8));
+ info_ptr->valid |= PNG_INFO_sBIT;
+}
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+void PNGAPI
+png_set_sRGB(png_structp png_ptr, png_infop info_ptr, int intent)
+{
+ png_debug1(1, "in %s storage function", "sRGB");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->srgb_intent = (png_byte)intent;
+ info_ptr->valid |= PNG_INFO_sRGB;
+}
+
+void PNGAPI
+png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
+ int intent)
+{
+#ifdef PNG_gAMA_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ float file_gamma;
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_fixed_point int_file_gamma;
+#endif
+#endif
+#ifdef PNG_cHRM_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
+#endif
+ png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y, int_green_x,
+ int_green_y, int_blue_x, int_blue_y;
+#endif
+ png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_set_sRGB(png_ptr, info_ptr, intent);
+
+#ifdef PNG_gAMA_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ file_gamma = (float).45455;
+ png_set_gAMA(png_ptr, info_ptr, file_gamma);
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ int_file_gamma = 45455L;
+ png_set_gAMA_fixed(png_ptr, info_ptr, int_file_gamma);
+#endif
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+ int_white_x = 31270L;
+ int_white_y = 32900L;
+ int_red_x = 64000L;
+ int_red_y = 33000L;
+ int_green_x = 30000L;
+ int_green_y = 60000L;
+ int_blue_x = 15000L;
+ int_blue_y = 6000L;
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ white_x = (float).3127;
+ white_y = (float).3290;
+ red_x = (float).64;
+ red_y = (float).33;
+ green_x = (float).30;
+ green_y = (float).60;
+ blue_x = (float).15;
+ blue_y = (float).06;
+#endif
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_set_cHRM_fixed(png_ptr, info_ptr,
+ int_white_x, int_white_y, int_red_x, int_red_y, int_green_x,
+ int_green_y, int_blue_x, int_blue_y);
+#endif
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ png_set_cHRM(png_ptr, info_ptr,
+ white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
+#endif
+#endif /* cHRM */
+}
+#endif /* sRGB */
+
+
+#ifdef PNG_iCCP_SUPPORTED
+void PNGAPI
+png_set_iCCP(png_structp png_ptr, png_infop info_ptr,
+ png_charp name, int compression_type,
+ png_charp profile, png_uint_32 proflen)
+{
+ png_charp new_iccp_name;
+ png_charp new_iccp_profile;
+ png_uint_32 length;
+
+ png_debug1(1, "in %s storage function", "iCCP");
+
+ if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
+ return;
+
+ length = png_strlen(name)+1;
+ new_iccp_name = (png_charp)png_malloc_warn(png_ptr, length);
+ if (new_iccp_name == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory to process iCCP chunk");
+ return;
+ }
+ png_memcpy(new_iccp_name, name, length);
+ new_iccp_profile = (png_charp)png_malloc_warn(png_ptr, proflen);
+ if (new_iccp_profile == NULL)
+ {
+ png_free (png_ptr, new_iccp_name);
+ png_warning(png_ptr,
+ "Insufficient memory to process iCCP profile");
+ return;
+ }
+ png_memcpy(new_iccp_profile, profile, (png_size_t)proflen);
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);
+
+ info_ptr->iccp_proflen = proflen;
+ info_ptr->iccp_name = new_iccp_name;
+ info_ptr->iccp_profile = new_iccp_profile;
+ /* Compression is always zero but is here so the API and info structure
+ * does not have to change if we introduce multiple compression types
+ */
+ info_ptr->iccp_compression = (png_byte)compression_type;
+ info_ptr->free_me |= PNG_FREE_ICCP;
+ info_ptr->valid |= PNG_INFO_iCCP;
+}
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+void PNGAPI
+png_set_text(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
+ int num_text)
+{
+ int ret;
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);
+ if (ret)
+ png_error(png_ptr, "Insufficient memory to store text");
+}
+
+int /* PRIVATE */
+png_set_text_2(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
+ int num_text)
+{
+ int i;
+
+ png_debug1(1, "in %s storage function", ((png_ptr == NULL ||
+ png_ptr->chunk_name[0] == '\0') ?
+ "text" : (png_const_charp)png_ptr->chunk_name));
+
+ if (png_ptr == NULL || info_ptr == NULL || num_text == 0)
+ return(0);
+
+ /* Make sure we have enough space in the "text" array in info_struct
+ * to hold all of the incoming text_ptr objects.
+ */
+ if (info_ptr->num_text + num_text > info_ptr->max_text)
+ {
+ if (info_ptr->text != NULL)
+ {
+ png_textp old_text;
+ int old_max;
+
+ old_max = info_ptr->max_text;
+ info_ptr->max_text = info_ptr->num_text + num_text + 8;
+ old_text = info_ptr->text;
+ info_ptr->text = (png_textp)png_malloc_warn(png_ptr,
+ (png_size_t)(info_ptr->max_text * png_sizeof(png_text)));
+ if (info_ptr->text == NULL)
+ {
+ png_free(png_ptr, old_text);
+ return(1);
+ }
+ png_memcpy(info_ptr->text, old_text, (png_size_t)(old_max *
+ png_sizeof(png_text)));
+ png_free(png_ptr, old_text);
+ }
+ else
+ {
+ info_ptr->max_text = num_text + 8;
+ info_ptr->num_text = 0;
+ info_ptr->text = (png_textp)png_malloc_warn(png_ptr,
+ (png_size_t)(info_ptr->max_text * png_sizeof(png_text)));
+ if (info_ptr->text == NULL)
+ return(1);
+ info_ptr->free_me |= PNG_FREE_TEXT;
+ }
+ png_debug1(3, "allocated %d entries for info_ptr->text",
+ info_ptr->max_text);
+ }
+ for (i = 0; i < num_text; i++)
+ {
+ png_size_t text_length, key_len;
+ png_size_t lang_len, lang_key_len;
+ png_textp textp = &(info_ptr->text[info_ptr->num_text]);
+
+ if (text_ptr[i].key == NULL)
+ continue;
+
+ key_len = png_strlen(text_ptr[i].key);
+
+ if (text_ptr[i].compression <= 0)
+ {
+ lang_len = 0;
+ lang_key_len = 0;
+ }
+
+ else
+#ifdef PNG_iTXt_SUPPORTED
+ {
+ /* Set iTXt data */
+
+ if (text_ptr[i].lang != NULL)
+ lang_len = png_strlen(text_ptr[i].lang);
+ else
+ lang_len = 0;
+ if (text_ptr[i].lang_key != NULL)
+ lang_key_len = png_strlen(text_ptr[i].lang_key);
+ else
+ lang_key_len = 0;
+ }
+#else /* PNG_iTXt_SUPPORTED */
+ {
+ png_warning(png_ptr, "iTXt chunk not supported");
+ continue;
+ }
+#endif
+
+ if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0')
+ {
+ text_length = 0;
+#ifdef PNG_iTXt_SUPPORTED
+ if (text_ptr[i].compression > 0)
+ textp->compression = PNG_ITXT_COMPRESSION_NONE;
+ else
+#endif
+ textp->compression = PNG_TEXT_COMPRESSION_NONE;
+ }
+
+ else
+ {
+ text_length = png_strlen(text_ptr[i].text);
+ textp->compression = text_ptr[i].compression;
+ }
+
+ textp->key = (png_charp)png_malloc_warn(png_ptr,
+ (png_size_t)
+ (key_len + text_length + lang_len + lang_key_len + 4));
+ if (textp->key == NULL)
+ return(1);
+ png_debug2(2, "Allocated %lu bytes at %x in png_set_text",
+ (unsigned long)(png_uint_32)
+ (key_len + lang_len + lang_key_len + text_length + 4),
+ (int)textp->key);
+
+ png_memcpy(textp->key, text_ptr[i].key,(png_size_t)(key_len));
+ *(textp->key + key_len) = '\0';
+#ifdef PNG_iTXt_SUPPORTED
+ if (text_ptr[i].compression > 0)
+ {
+ textp->lang = textp->key + key_len + 1;
+ png_memcpy(textp->lang, text_ptr[i].lang, lang_len);
+ *(textp->lang + lang_len) = '\0';
+ textp->lang_key = textp->lang + lang_len + 1;
+ png_memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
+ *(textp->lang_key + lang_key_len) = '\0';
+ textp->text = textp->lang_key + lang_key_len + 1;
+ }
+ else
+#endif
+ {
+#ifdef PNG_iTXt_SUPPORTED
+ textp->lang=NULL;
+ textp->lang_key=NULL;
+#endif
+ textp->text = textp->key + key_len + 1;
+ }
+ if (text_length)
+ png_memcpy(textp->text, text_ptr[i].text,
+ (png_size_t)(text_length));
+ *(textp->text + text_length) = '\0';
+
+#ifdef PNG_iTXt_SUPPORTED
+ if (textp->compression > 0)
+ {
+ textp->text_length = 0;
+ textp->itxt_length = text_length;
+ }
+ else
+#endif
+
+ {
+ textp->text_length = text_length;
+#ifdef PNG_iTXt_SUPPORTED
+ textp->itxt_length = 0;
+#endif
+ }
+ info_ptr->num_text++;
+ png_debug1(3, "transferred text chunk %d", info_ptr->num_text);
+ }
+ return(0);
+}
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+void PNGAPI
+png_set_tIME(png_structp png_ptr, png_infop info_ptr, png_timep mod_time)
+{
+ png_debug1(1, "in %s storage function", "tIME");
+
+ if (png_ptr == NULL || info_ptr == NULL ||
+ (png_ptr->mode & PNG_WROTE_tIME))
+ return;
+
+ png_memcpy(&(info_ptr->mod_time), mod_time, png_sizeof(png_time));
+ info_ptr->valid |= PNG_INFO_tIME;
+}
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+void PNGAPI
+png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
+ png_bytep trans_alpha, int num_trans, png_color_16p trans_color)
+{
+ png_debug1(1, "in %s storage function", "tRNS");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (trans_alpha != NULL)
+ {
+ /* It may not actually be necessary to set png_ptr->trans_alpha here;
+ * we do it for backward compatibility with the way the png_handle_tRNS
+ * function used to do the allocation.
+ */
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
+
+ /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
+ png_ptr->trans_alpha = info_ptr->trans_alpha = (png_bytep)png_malloc(png_ptr,
+ (png_size_t)PNG_MAX_PALETTE_LENGTH);
+ if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
+ png_memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
+ }
+
+ if (trans_color != NULL)
+ {
+ int sample_max = (1 << info_ptr->bit_depth);
+ if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
+ (int)trans_color->gray > sample_max) ||
+ (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
+ ((int)trans_color->red > sample_max ||
+ (int)trans_color->green > sample_max ||
+ (int)trans_color->blue > sample_max)))
+ png_warning(png_ptr,
+ "tRNS chunk has out-of-range samples for bit_depth");
+ png_memcpy(&(info_ptr->trans_color), trans_color,
+ png_sizeof(png_color_16));
+ if (num_trans == 0)
+ num_trans = 1;
+ }
+
+ info_ptr->num_trans = (png_uint_16)num_trans;
+ if (num_trans != 0)
+ {
+ info_ptr->valid |= PNG_INFO_tRNS;
+ info_ptr->free_me |= PNG_FREE_TRNS;
+ }
+}
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+void PNGAPI
+png_set_sPLT(png_structp png_ptr,
+ png_infop info_ptr, png_sPLT_tp entries, int nentries)
+/*
+ * entries - array of png_sPLT_t structures
+ * to be added to the list of palettes
+ * in the info structure.
+ * nentries - number of palette structures to be
+ * added.
+ */
+{
+ png_sPLT_tp np;
+ int i;
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ np = (png_sPLT_tp)png_malloc_warn(png_ptr,
+ (info_ptr->splt_palettes_num + nentries) *
+ (png_size_t)png_sizeof(png_sPLT_t));
+ if (np == NULL)
+ {
+ png_warning(png_ptr, "No memory for sPLT palettes");
+ return;
+ }
+
+ png_memcpy(np, info_ptr->splt_palettes,
+ info_ptr->splt_palettes_num * png_sizeof(png_sPLT_t));
+ png_free(png_ptr, info_ptr->splt_palettes);
+ info_ptr->splt_palettes=NULL;
+
+ for (i = 0; i < nentries; i++)
+ {
+ png_sPLT_tp to = np + info_ptr->splt_palettes_num + i;
+ png_sPLT_tp from = entries + i;
+ png_uint_32 length;
+
+ length = png_strlen(from->name) + 1;
+ to->name = (png_charp)png_malloc_warn(png_ptr, (png_size_t)length);
+ if (to->name == NULL)
+ {
+ png_warning(png_ptr,
+ "Out of memory while processing sPLT chunk");
+ continue;
+ }
+ png_memcpy(to->name, from->name, length);
+ to->entries = (png_sPLT_entryp)png_malloc_warn(png_ptr,
+ (png_size_t)(from->nentries * png_sizeof(png_sPLT_entry)));
+ if (to->entries == NULL)
+ {
+ png_warning(png_ptr,
+ "Out of memory while processing sPLT chunk");
+ png_free(png_ptr, to->name);
+ to->name = NULL;
+ continue;
+ }
+ png_memcpy(to->entries, from->entries,
+ from->nentries * png_sizeof(png_sPLT_entry));
+ to->nentries = from->nentries;
+ to->depth = from->depth;
+ }
+
+ info_ptr->splt_palettes = np;
+ info_ptr->splt_palettes_num += nentries;
+ info_ptr->valid |= PNG_INFO_sPLT;
+ info_ptr->free_me |= PNG_FREE_SPLT;
+}
+#endif /* PNG_sPLT_SUPPORTED */
+
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+void PNGAPI
+png_set_unknown_chunks(png_structp png_ptr,
+ png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns)
+{
+ png_unknown_chunkp np;
+ int i;
+
+ if (png_ptr == NULL || info_ptr == NULL || num_unknowns == 0)
+ return;
+
+ np = (png_unknown_chunkp)png_malloc_warn(png_ptr,
+ (png_size_t)((info_ptr->unknown_chunks_num + num_unknowns) *
+ png_sizeof(png_unknown_chunk)));
+ if (np == NULL)
+ {
+ png_warning(png_ptr,
+ "Out of memory while processing unknown chunk");
+ return;
+ }
+
+ png_memcpy(np, info_ptr->unknown_chunks,
+ info_ptr->unknown_chunks_num * png_sizeof(png_unknown_chunk));
+ png_free(png_ptr, info_ptr->unknown_chunks);
+ info_ptr->unknown_chunks = NULL;
+
+ for (i = 0; i < num_unknowns; i++)
+ {
+ png_unknown_chunkp to = np + info_ptr->unknown_chunks_num + i;
+ png_unknown_chunkp from = unknowns + i;
+
+ png_memcpy((png_charp)to->name, (png_charp)from->name,
+ png_sizeof(from->name));
+ to->name[png_sizeof(to->name)-1] = '\0';
+ to->size = from->size;
+ /* Note our location in the read or write sequence */
+ to->location = (png_byte)(png_ptr->mode & 0xff);
+
+ if (from->size == 0)
+ to->data=NULL;
+ else
+ {
+ to->data = (png_bytep)png_malloc_warn(png_ptr,
+ (png_size_t)from->size);
+ if (to->data == NULL)
+ {
+ png_warning(png_ptr,
+ "Out of memory while processing unknown chunk");
+ to->size = 0;
+ }
+ else
+ png_memcpy(to->data, from->data, from->size);
+ }
+ }
+
+ info_ptr->unknown_chunks = np;
+ info_ptr->unknown_chunks_num += num_unknowns;
+ info_ptr->free_me |= PNG_FREE_UNKN;
+}
+void PNGAPI
+png_set_unknown_chunk_location(png_structp png_ptr, png_infop info_ptr,
+ int chunk, int location)
+{
+ if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 && chunk <
+ (int)info_ptr->unknown_chunks_num)
+ info_ptr->unknown_chunks[chunk].location = (png_byte)location;
+}
+#endif
+
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+png_uint_32 PNGAPI
+png_permit_mng_features (png_structp png_ptr, png_uint_32 mng_features)
+{
+ png_debug(1, "in png_permit_mng_features");
+
+ if (png_ptr == NULL)
+ return (png_uint_32)0;
+ png_ptr->mng_features_permitted =
+ (png_byte)(mng_features & PNG_ALL_MNG_FEATURES);
+ return (png_uint_32)png_ptr->mng_features_permitted;
+}
+#endif
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+void PNGAPI
+png_set_keep_unknown_chunks(png_structp png_ptr, int keep, png_bytep
+ chunk_list, int num_chunks)
+{
+ png_bytep new_list, p;
+ int i, old_num_chunks;
+ if (png_ptr == NULL)
+ return;
+ if (num_chunks == 0)
+ {
+ if (keep == PNG_HANDLE_CHUNK_ALWAYS || keep == PNG_HANDLE_CHUNK_IF_SAFE)
+ png_ptr->flags |= PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
+ else
+ png_ptr->flags &= ~PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
+
+ if (keep == PNG_HANDLE_CHUNK_ALWAYS)
+ png_ptr->flags |= PNG_FLAG_KEEP_UNSAFE_CHUNKS;
+ else
+ png_ptr->flags &= ~PNG_FLAG_KEEP_UNSAFE_CHUNKS;
+ return;
+ }
+ if (chunk_list == NULL)
+ return;
+ old_num_chunks = png_ptr->num_chunk_list;
+ new_list=(png_bytep)png_malloc(png_ptr,
+ (png_size_t)
+ (5*(num_chunks + old_num_chunks)));
+ if (png_ptr->chunk_list != NULL)
+ {
+ png_memcpy(new_list, png_ptr->chunk_list,
+ (png_size_t)(5*old_num_chunks));
+ png_free(png_ptr, png_ptr->chunk_list);
+ png_ptr->chunk_list=NULL;
+ }
+ png_memcpy(new_list + 5*old_num_chunks, chunk_list,
+ (png_size_t)(5*num_chunks));
+ for (p = new_list + 5*old_num_chunks + 4, i = 0; i<num_chunks; i++, p += 5)
+ *p=(png_byte)keep;
+ png_ptr->num_chunk_list = old_num_chunks + num_chunks;
+ png_ptr->chunk_list = new_list;
+ png_ptr->free_me |= PNG_FREE_LIST;
+}
+#endif
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+void PNGAPI
+png_set_read_user_chunk_fn(png_structp png_ptr, png_voidp user_chunk_ptr,
+ png_user_chunk_ptr read_user_chunk_fn)
+{
+ png_debug(1, "in png_set_read_user_chunk_fn");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->read_user_chunk_fn = read_user_chunk_fn;
+ png_ptr->user_chunk_ptr = user_chunk_ptr;
+}
+#endif
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_set_rows(png_structp png_ptr, png_infop info_ptr, png_bytepp row_pointers)
+{
+ png_debug1(1, "in %s storage function", "rows");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (info_ptr->row_pointers && (info_ptr->row_pointers != row_pointers))
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+ info_ptr->row_pointers = row_pointers;
+ if (row_pointers)
+ info_ptr->valid |= PNG_INFO_IDAT;
+}
+#endif
+
+void PNGAPI
+png_set_compression_buffer_size(png_structp png_ptr,
+ png_size_t size)
+{
+ if (png_ptr == NULL)
+ return;
+ png_free(png_ptr, png_ptr->zbuf);
+ png_ptr->zbuf_size = size;
+ png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, size);
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+}
+
+void PNGAPI
+png_set_invalid(png_structp png_ptr, png_infop info_ptr, int mask)
+{
+ if (png_ptr && info_ptr)
+ info_ptr->valid &= ~mask;
+}
+
+
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* This function was added to libpng 1.2.6 */
+void PNGAPI
+png_set_user_limits (png_structp png_ptr, png_uint_32 user_width_max,
+ png_uint_32 user_height_max)
+{
+ /* Images with dimensions larger than these limits will be
+ * rejected by png_set_IHDR(). To accept any PNG datastream
+ * regardless of dimensions, set both limits to 0x7ffffffL.
+ */
+ if (png_ptr == NULL)
+ return;
+ png_ptr->user_width_max = user_width_max;
+ png_ptr->user_height_max = user_height_max;
+}
+
+/* This function was added to libpng 1.4.0 */
+void PNGAPI
+png_set_chunk_cache_max (png_structp png_ptr,
+ png_uint_32 user_chunk_cache_max)
+{
+ if (png_ptr)
+ png_ptr->user_chunk_cache_max = user_chunk_cache_max;
+}
+
+/* This function was added to libpng 1.4.1 */
+void PNGAPI
+png_set_chunk_malloc_max (png_structp png_ptr,
+ png_alloc_size_t user_chunk_malloc_max)
+{
+ if (png_ptr)
+ png_ptr->user_chunk_malloc_max =
+ (png_size_t)user_chunk_malloc_max;
+}
+#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
+
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_set_benign_errors(png_structp png_ptr, int allowed)
+{
+ png_debug(1, "in png_set_benign_errors");
+
+ if (allowed)
+ png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
+ else
+ png_ptr->flags &= ~PNG_FLAG_BENIGN_ERRORS_WARN;
+}
+#endif /* PNG_BENIGN_ERRORS_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
--- /dev/null
+
+/* pngtrans.c - transforms the data in a row (used by both readers and writers)
+ *
+ * Last changed in libpng 1.4.2 [April 29, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#include "pngpriv.h"
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Turn on BGR-to-RGB mapping */
+void PNGAPI
+png_set_bgr(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_bgr");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->transformations |= PNG_BGR;
+}
+#endif
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Turn on 16 bit byte swapping */
+void PNGAPI
+png_set_swap(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_swap");
+
+ if (png_ptr == NULL)
+ return;
+ if (png_ptr->bit_depth == 16)
+ png_ptr->transformations |= PNG_SWAP_BYTES;
+}
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+/* Turn on pixel packing */
+void PNGAPI
+png_set_packing(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_packing");
+
+ if (png_ptr == NULL)
+ return;
+ if (png_ptr->bit_depth < 8)
+ {
+ png_ptr->transformations |= PNG_PACK;
+ png_ptr->usr_bit_depth = 8;
+ }
+}
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* Turn on packed pixel swapping */
+void PNGAPI
+png_set_packswap(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_packswap");
+
+ if (png_ptr == NULL)
+ return;
+ if (png_ptr->bit_depth < 8)
+ png_ptr->transformations |= PNG_PACKSWAP;
+}
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+void PNGAPI
+png_set_shift(png_structp png_ptr, png_color_8p true_bits)
+{
+ png_debug(1, "in png_set_shift");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->transformations |= PNG_SHIFT;
+ png_ptr->shift = *true_bits;
+}
+#endif
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+ defined(PNG_WRITE_INTERLACING_SUPPORTED)
+int PNGAPI
+png_set_interlace_handling(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_interlace handling");
+
+ if (png_ptr && png_ptr->interlaced)
+ {
+ png_ptr->transformations |= PNG_INTERLACE;
+ return (7);
+ }
+
+ return (1);
+}
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte on read, or remove a filler or alpha byte on write.
+ * The filler type has changed in v0.95 to allow future 2-byte fillers
+ * for 48-bit input data, as well as to avoid problems with some compilers
+ * that don't like bytes as parameters.
+ */
+void PNGAPI
+png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
+{
+ png_debug(1, "in png_set_filler");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->transformations |= PNG_FILLER;
+ png_ptr->filler = (png_uint_16)filler;
+ if (filler_loc == PNG_FILLER_AFTER)
+ png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
+ else
+ png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
+
+ /* This should probably go in the "do_read_filler" routine.
+ * I attempted to do that in libpng-1.0.1a but that caused problems
+ * so I restored it in libpng-1.0.2a
+ */
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ png_ptr->usr_channels = 4;
+ }
+
+ /* Also I added this in libpng-1.0.2a (what happens when we expand
+ * a less-than-8-bit grayscale to GA? */
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
+ {
+ png_ptr->usr_channels = 2;
+ }
+}
+
+/* Added to libpng-1.2.7 */
+void PNGAPI
+png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc)
+{
+ png_debug(1, "in png_set_add_alpha");
+
+ if (png_ptr == NULL)
+ return;
+ png_set_filler(png_ptr, filler, filler_loc);
+ png_ptr->transformations |= PNG_ADD_ALPHA;
+}
+
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_swap_alpha(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_swap_alpha");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->transformations |= PNG_SWAP_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_invert_alpha(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_invert_alpha");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->transformations |= PNG_INVERT_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+void PNGAPI
+png_set_invert_mono(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_invert_mono");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->transformations |= PNG_INVERT_MONO;
+}
+
+/* Invert monochrome grayscale data */
+void /* PRIVATE */
+png_do_invert(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_invert");
+
+ /* This test removed from libpng version 1.0.13 and 1.2.0:
+ * if (row_info->bit_depth == 1 &&
+ */
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ png_bytep rp = row;
+ png_uint_32 i;
+ png_uint_32 istop = row_info->rowbytes;
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(~(*rp));
+ rp++;
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+ row_info->bit_depth == 8)
+ {
+ png_bytep rp = row;
+ png_uint_32 i;
+ png_uint_32 istop = row_info->rowbytes;
+
+ for (i = 0; i < istop; i+=2)
+ {
+ *rp = (png_byte)(~(*rp));
+ rp+=2;
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+ row_info->bit_depth == 16)
+ {
+ png_bytep rp = row;
+ png_uint_32 i;
+ png_uint_32 istop = row_info->rowbytes;
+
+ for (i = 0; i < istop; i+=4)
+ {
+ *rp = (png_byte)(~(*rp));
+ *(rp+1) = (png_byte)(~(*(rp+1)));
+ rp+=4;
+ }
+ }
+}
+#endif
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Swaps byte order on 16 bit depth images */
+void /* PRIVATE */
+png_do_swap(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_swap");
+
+ if (
+ row_info->bit_depth == 16)
+ {
+ png_bytep rp = row;
+ png_uint_32 i;
+ png_uint_32 istop= row_info->width * row_info->channels;
+
+ for (i = 0; i < istop; i++, rp += 2)
+ {
+ png_byte t = *rp;
+ *rp = *(rp + 1);
+ *(rp + 1) = t;
+ }
+ }
+}
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+static PNG_CONST png_byte onebppswaptable[256] = {
+ 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
+ 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
+ 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
+ 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
+ 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4,
+ 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
+ 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,
+ 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
+ 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,
+ 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
+ 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA,
+ 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
+ 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6,
+ 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
+ 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,
+ 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
+ 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,
+ 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
+ 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9,
+ 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
+ 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
+ 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
+ 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED,
+ 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
+ 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3,
+ 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
+ 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,
+ 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
+ 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7,
+ 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
+ 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF,
+ 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
+};
+
+static PNG_CONST png_byte twobppswaptable[256] = {
+ 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,
+ 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,
+ 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,
+ 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4,
+ 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8,
+ 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8,
+ 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC,
+ 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC,
+ 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1,
+ 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1,
+ 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5,
+ 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5,
+ 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9,
+ 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9,
+ 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD,
+ 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD,
+ 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2,
+ 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2,
+ 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6,
+ 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6,
+ 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA,
+ 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA,
+ 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE,
+ 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE,
+ 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3,
+ 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3,
+ 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7,
+ 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7,
+ 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB,
+ 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB,
+ 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF,
+ 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF
+};
+
+static PNG_CONST png_byte fourbppswaptable[256] = {
+ 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
+ 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,
+ 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,
+ 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1,
+ 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72,
+ 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2,
+ 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73,
+ 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3,
+ 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74,
+ 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4,
+ 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75,
+ 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5,
+ 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76,
+ 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6,
+ 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77,
+ 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7,
+ 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78,
+ 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8,
+ 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79,
+ 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9,
+ 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A,
+ 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA,
+ 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B,
+ 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB,
+ 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C,
+ 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC,
+ 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D,
+ 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD,
+ 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E,
+ 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE,
+ 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F,
+ 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF
+};
+
+/* Swaps pixel packing order within bytes */
+void /* PRIVATE */
+png_do_packswap(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_packswap");
+
+ if (
+ row_info->bit_depth < 8)
+ {
+ png_bytep rp, end, table;
+
+ end = row + row_info->rowbytes;
+
+ if (row_info->bit_depth == 1)
+ table = (png_bytep)onebppswaptable;
+ else if (row_info->bit_depth == 2)
+ table = (png_bytep)twobppswaptable;
+ else if (row_info->bit_depth == 4)
+ table = (png_bytep)fourbppswaptable;
+ else
+ return;
+
+ for (rp = row; rp < end; rp++)
+ *rp = table[*rp];
+ }
+}
+#endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+ defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+/* Remove filler or alpha byte(s) */
+void /* PRIVATE */
+png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags)
+{
+ png_debug(1, "in png_do_strip_filler");
+
+ {
+ png_bytep sp=row;
+ png_bytep dp=row;
+ png_uint_32 row_width=row_info->width;
+ png_uint_32 i;
+
+ if ((row_info->color_type == PNG_COLOR_TYPE_RGB ||
+ (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
+ (flags & PNG_FLAG_STRIP_ALPHA))) &&
+ row_info->channels == 4)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This converts from RGBX or RGBA to RGB */
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ dp+=3; sp+=4;
+ for (i = 1; i < row_width; i++)
+ {
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ sp++;
+ }
+ }
+ /* This converts from XRGB or ARGB to RGB */
+ else
+ {
+ for (i = 0; i < row_width; i++)
+ {
+ sp++;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ }
+ }
+ row_info->pixel_depth = 24;
+ row_info->rowbytes = row_width * 3;
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */
+ sp += 8; dp += 6;
+ for (i = 1; i < row_width; i++)
+ {
+ /* This could be (although png_memcpy is probably slower):
+ png_memcpy(dp, sp, 6);
+ sp += 8;
+ dp += 6;
+ */
+
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ sp += 2;
+ }
+ }
+ else
+ {
+ /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */
+ for (i = 0; i < row_width; i++)
+ {
+ /* This could be (although png_memcpy is probably slower):
+ png_memcpy(dp, sp, 6);
+ sp += 8;
+ dp += 6;
+ */
+
+ sp+=2;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ }
+ }
+ row_info->pixel_depth = 48;
+ row_info->rowbytes = row_width * 6;
+ }
+ row_info->channels = 3;
+ }
+ else if ((row_info->color_type == PNG_COLOR_TYPE_GRAY ||
+ (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+ (flags & PNG_FLAG_STRIP_ALPHA))) &&
+ row_info->channels == 2)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This converts from GX or GA to G */
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ for (i = 0; i < row_width; i++)
+ {
+ *dp++ = *sp++;
+ sp++;
+ }
+ }
+ /* This converts from XG or AG to G */
+ else
+ {
+ for (i = 0; i < row_width; i++)
+ {
+ sp++;
+ *dp++ = *sp++;
+ }
+ }
+ row_info->pixel_depth = 8;
+ row_info->rowbytes = row_width;
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ /* This converts from GGXX or GGAA to GG */
+ sp += 4; dp += 2;
+ for (i = 1; i < row_width; i++)
+ {
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ sp += 2;
+ }
+ }
+ else
+ {
+ /* This converts from XXGG or AAGG to GG */
+ for (i = 0; i < row_width; i++)
+ {
+ sp += 2;
+ *dp++ = *sp++;
+ *dp++ = *sp++;
+ }
+ }
+ row_info->pixel_depth = 16;
+ row_info->rowbytes = row_width * 2;
+ }
+ row_info->channels = 1;
+ }
+ if (flags & PNG_FLAG_STRIP_ALPHA)
+ row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
+ }
+}
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Swaps red and blue bytes within a pixel */
+void /* PRIVATE */
+png_do_bgr(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_bgr");
+
+ if (
+ (row_info->color_type & PNG_COLOR_MASK_COLOR))
+ {
+ png_uint_32 row_width = row_info->width;
+ if (row_info->bit_depth == 8)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 3)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 2);
+ *(rp + 2) = save;
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 4)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 2);
+ *(rp + 2) = save;
+ }
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 6)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 4);
+ *(rp + 4) = save;
+ save = *(rp + 1);
+ *(rp + 1) = *(rp + 5);
+ *(rp + 5) = save;
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 8)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 4);
+ *(rp + 4) = save;
+ save = *(rp + 1);
+ *(rp + 1) = *(rp + 5);
+ *(rp + 5) = save;
+ }
+ }
+ }
+ }
+}
+#endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+void PNGAPI
+png_set_user_transform_info(png_structp png_ptr, png_voidp
+ user_transform_ptr, int user_transform_depth, int user_transform_channels)
+{
+ png_debug(1, "in png_set_user_transform_info");
+
+ if (png_ptr == NULL)
+ return;
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+ png_ptr->user_transform_ptr = user_transform_ptr;
+ png_ptr->user_transform_depth = (png_byte)user_transform_depth;
+ png_ptr->user_transform_channels = (png_byte)user_transform_channels;
+#else
+ if (user_transform_ptr || user_transform_depth || user_transform_channels)
+ png_warning(png_ptr,
+ "This version of libpng does not support user transform info");
+#endif
+}
+
+/* This function returns a pointer to the user_transform_ptr associated with
+ * the user transform functions. The application should free any memory
+ * associated with this pointer before png_write_destroy and png_read_destroy
+ * are called.
+ */
+png_voidp PNGAPI
+png_get_user_transform_ptr(png_structp png_ptr)
+{
+ if (png_ptr == NULL)
+ return (NULL);
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+ return ((png_voidp)png_ptr->user_transform_ptr);
+#else
+ return (NULL);
+#endif
+}
+#endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||
+ PNG_WRITE_USER_TRANSFORM_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
--- /dev/null
+
+/* pngwio.c - functions for data output
+ *
+ * Last changed in libpng 1.4.0 [January 3, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all output. Users who need
+ * special handling are expected to write functions that have the same
+ * arguments as these and perform similar functions, but that possibly
+ * use different output methods. Note that you shouldn't change these
+ * functions, but rather write replacement functions and then change
+ * them at run time with png_set_write_fn(...).
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#ifdef PNG_WRITE_SUPPORTED
+#include "pngpriv.h"
+
+/* Write the data to whatever output you are using. The default routine
+ * writes to a file pointer. Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered writes. This should never be asked
+ * to write more than 64K on a 16 bit machine.
+ */
+
+void /* PRIVATE */
+png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+ if (png_ptr->write_data_fn != NULL )
+ (*(png_ptr->write_data_fn))(png_ptr, data, length);
+ else
+ png_error(png_ptr, "Call to NULL write function");
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual writing of data. If you are
+ * not writing to a standard C stream, you should create a replacement
+ * write_data function and use it at run time with png_set_write_fn(), rather
+ * than changing the library.
+ */
+#ifndef USE_FAR_KEYWORD
+void PNGAPI
+png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+ png_uint_32 check;
+
+ if (png_ptr == NULL)
+ return;
+ check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
+ if (check != length)
+ png_error(png_ptr, "Write Error");
+}
+#else
+/* This is the model-independent version. Since the standard I/O library
+ * can't handle far buffers in the medium and small models, we have to copy
+ * the data.
+ */
+
+#define NEAR_BUF_SIZE 1024
+#define MIN(a,b) (a <= b ? a : b)
+
+void PNGAPI
+png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+ png_uint_32 check;
+ png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */
+ png_FILE_p io_ptr;
+
+ if (png_ptr == NULL)
+ return;
+ /* Check if data really is near. If so, use usual code. */
+ near_data = (png_byte *)CVT_PTR_NOCHECK(data);
+ io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
+ if ((png_bytep)near_data == data)
+ {
+ check = fwrite(near_data, 1, length, io_ptr);
+ }
+ else
+ {
+ png_byte buf[NEAR_BUF_SIZE];
+ png_size_t written, remaining, err;
+ check = 0;
+ remaining = length;
+ do
+ {
+ written = MIN(NEAR_BUF_SIZE, remaining);
+ png_memcpy(buf, data, written); /* Copy far buffer to near buffer */
+ err = fwrite(buf, 1, written, io_ptr);
+ if (err != written)
+ break;
+
+ else
+ check += err;
+
+ data += written;
+ remaining -= written;
+ }
+ while (remaining != 0);
+ }
+ if (check != length)
+ png_error(png_ptr, "Write Error");
+}
+
+#endif
+#endif
+
+/* This function is called to output any data pending writing (normally
+ * to disk). After png_flush is called, there should be no data pending
+ * writing in any buffers.
+ */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+void /* PRIVATE */
+png_flush(png_structp png_ptr)
+{
+ if (png_ptr->output_flush_fn != NULL)
+ (*(png_ptr->output_flush_fn))(png_ptr);
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+void PNGAPI
+png_default_flush(png_structp png_ptr)
+{
+ png_FILE_p io_ptr;
+ if (png_ptr == NULL)
+ return;
+ io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
+ fflush(io_ptr);
+}
+#endif
+#endif
+
+/* This function allows the application to supply new output functions for
+ * libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ * png_ptr - pointer to a png output data structure
+ * io_ptr - pointer to user supplied structure containing info about
+ * the output functions. May be NULL.
+ * write_data_fn - pointer to a new output function that takes as its
+ * arguments a pointer to a png_struct, a pointer to
+ * data to be written, and a 32-bit unsigned int that is
+ * the number of bytes to be written. The new write
+ * function should call png_error(png_ptr, "Error msg")
+ * to exit and output any fatal error messages. May be
+ * NULL, in which case libpng's default function will
+ * be used.
+ * flush_data_fn - pointer to a new flush function that takes as its
+ * arguments a pointer to a png_struct. After a call to
+ * the flush function, there should be no data in any buffers
+ * or pending transmission. If the output method doesn't do
+ * any buffering of output, a function prototype must still be
+ * supplied although it doesn't have to do anything. If
+ * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
+ * time, output_flush_fn will be ignored, although it must be
+ * supplied for compatibility. May be NULL, in which case
+ * libpng's default function will be used, if
+ * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not
+ * a good idea if io_ptr does not point to a standard
+ * *FILE structure.
+ */
+void PNGAPI
+png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
+ png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->io_ptr = io_ptr;
+
+#ifdef PNG_STDIO_SUPPORTED
+ if (write_data_fn != NULL)
+ png_ptr->write_data_fn = write_data_fn;
+
+ else
+ png_ptr->write_data_fn = png_default_write_data;
+#else
+ png_ptr->write_data_fn = write_data_fn;
+#endif
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+#ifdef PNG_STDIO_SUPPORTED
+ if (output_flush_fn != NULL)
+ png_ptr->output_flush_fn = output_flush_fn;
+
+ else
+ png_ptr->output_flush_fn = png_default_flush;
+#else
+ png_ptr->output_flush_fn = output_flush_fn;
+#endif
+#endif /* PNG_WRITE_FLUSH_SUPPORTED */
+
+ /* It is an error to read while writing a png file */
+ if (png_ptr->read_data_fn != NULL)
+ {
+ png_ptr->read_data_fn = NULL;
+ png_warning(png_ptr,
+ "Attempted to set both read_data_fn and write_data_fn in");
+ png_warning(png_ptr,
+ "the same structure. Resetting read_data_fn to NULL");
+ }
+}
+
+#ifdef USE_FAR_KEYWORD
+#ifdef _MSC_VER
+void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
+{
+ void *near_ptr;
+ void FAR *far_ptr;
+ FP_OFF(near_ptr) = FP_OFF(ptr);
+ far_ptr = (void FAR *)near_ptr;
+
+ if (check != 0)
+ if (FP_SEG(ptr) != FP_SEG(far_ptr))
+ png_error(png_ptr, "segment lost in conversion");
+
+ return(near_ptr);
+}
+# else
+void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
+{
+ void *near_ptr;
+ void FAR *far_ptr;
+ near_ptr = (void FAR *)ptr;
+ far_ptr = (void FAR *)near_ptr;
+
+ if (check != 0)
+ if (far_ptr != ptr)
+ png_error(png_ptr, "segment lost in conversion");
+
+ return(near_ptr);
+}
+# endif
+# endif
+#endif /* PNG_WRITE_SUPPORTED */
--- /dev/null
+
+/* pngwrite.c - general routines to write a PNG file
+ *
+ * Last changed in libpng 1.4.0 [January 3, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* Get internal access to png.h */
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#ifdef PNG_WRITE_SUPPORTED
+#include "pngpriv.h"
+
+/* Writes all the PNG information. This is the suggested way to use the
+ * library. If you have a new chunk to add, make a function to write it,
+ * and put it in the correct location here. If you want the chunk written
+ * after the image data, put it in png_write_end(). I strongly encourage
+ * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
+ * the chunk, as that will keep the code from breaking if you want to just
+ * write a plain PNG file. If you have long comments, I suggest writing
+ * them in png_write_end(), and compressing them.
+ */
+void PNGAPI
+png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
+{
+ png_debug(1, "in png_write_info_before_PLTE");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+ if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
+ {
+ /* Write PNG signature */
+ png_write_sig(png_ptr);
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
+ (png_ptr->mng_features_permitted))
+ {
+ png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+ png_ptr->mng_features_permitted = 0;
+ }
+#endif
+ /* Write IHDR information. */
+ png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
+ info_ptr->filter_type,
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ info_ptr->interlace_type);
+#else
+ 0);
+#endif
+ /* The rest of these check to see if the valid field has the appropriate
+ * flag set, and if it does, writes the chunk.
+ */
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_gAMA)
+ {
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+ png_write_gAMA(png_ptr, info_ptr->gamma);
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
+# endif
+#endif
+ }
+#endif
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_sRGB)
+ png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
+#endif
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_iCCP)
+ png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
+ info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
+#endif
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_sBIT)
+ png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
+#endif
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_cHRM)
+ {
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ png_write_cHRM(png_ptr,
+ info_ptr->x_white, info_ptr->y_white,
+ info_ptr->x_red, info_ptr->y_red,
+ info_ptr->x_green, info_ptr->y_green,
+ info_ptr->x_blue, info_ptr->y_blue);
+#else
+# ifdef PNG_FIXED_POINT_SUPPORTED
+ png_write_cHRM_fixed(png_ptr,
+ info_ptr->int_x_white, info_ptr->int_y_white,
+ info_ptr->int_x_red, info_ptr->int_y_red,
+ info_ptr->int_x_green, info_ptr->int_y_green,
+ info_ptr->int_x_blue, info_ptr->int_y_blue);
+# endif
+#endif
+ }
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ if (info_ptr->unknown_chunks_num)
+ {
+ png_unknown_chunk *up;
+
+ png_debug(5, "writing extra chunks");
+
+ for (up = info_ptr->unknown_chunks;
+ up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+ up++)
+ {
+ int keep = png_handle_as_unknown(png_ptr, up->name);
+ if (keep != PNG_HANDLE_CHUNK_NEVER &&
+ up->location && !(up->location & PNG_HAVE_PLTE) &&
+ !(up->location & PNG_HAVE_IDAT) &&
+ ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+ {
+ if (up->size == 0)
+ png_warning(png_ptr, "Writing zero-length unknown chunk");
+ png_write_chunk(png_ptr, up->name, up->data, up->size);
+ }
+ }
+ }
+#endif
+ png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
+ }
+}
+
+void PNGAPI
+png_write_info(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+ int i;
+#endif
+
+ png_debug(1, "in png_write_info");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_write_info_before_PLTE(png_ptr, info_ptr);
+
+ if (info_ptr->valid & PNG_INFO_PLTE)
+ png_write_PLTE(png_ptr, info_ptr->palette,
+ (png_uint_32)info_ptr->num_palette);
+ else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ png_error(png_ptr, "Valid palette required for paletted images");
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_tRNS)
+ {
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ /* Invert the alpha channel (in tRNS) */
+ if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
+ info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ int j;
+ for (j = 0; j<(int)info_ptr->num_trans; j++)
+ info_ptr->trans_alpha[j] = (png_byte)(255 - info_ptr->trans_alpha[j]);
+ }
+#endif
+ png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
+ info_ptr->num_trans, info_ptr->color_type);
+ }
+#endif
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_bKGD)
+ png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
+#endif
+#ifdef PNG_WRITE_hIST_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_hIST)
+ png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
+#endif
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_oFFs)
+ png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
+ info_ptr->offset_unit_type);
+#endif
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_pCAL)
+ png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
+ info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
+ info_ptr->pcal_units, info_ptr->pcal_params);
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_sCAL)
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
+ png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
+ info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
+#else /* !FLOATING_POINT */
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
+ info_ptr->scal_s_width, info_ptr->scal_s_height);
+#endif /* FIXED_POINT */
+#endif /* FLOATING_POINT */
+#else /* !WRITE_sCAL */
+ png_warning(png_ptr,
+ "png_write_sCAL not supported; sCAL chunk not written");
+#endif /* WRITE_sCAL */
+#endif /* sCAL */
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_pHYs)
+ png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
+ info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
+#endif /* pHYs */
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_tIME)
+ {
+ png_write_tIME(png_ptr, &(info_ptr->mod_time));
+ png_ptr->mode |= PNG_WROTE_tIME;
+ }
+#endif /* tIME */
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_sPLT)
+ for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+ png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
+#endif /* sPLT */
+
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ /* Check to see if we need to write text chunks */
+ for (i = 0; i < info_ptr->num_text; i++)
+ {
+ png_debug2(2, "Writing header text chunk %d, type %d", i,
+ info_ptr->text[i].compression);
+ /* An internationalized chunk? */
+ if (info_ptr->text[i].compression > 0)
+ {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+ /* Write international chunk */
+ png_write_iTXt(png_ptr,
+ info_ptr->text[i].compression,
+ info_ptr->text[i].key,
+ info_ptr->text[i].lang,
+ info_ptr->text[i].lang_key,
+ info_ptr->text[i].text);
+#else
+ png_warning(png_ptr, "Unable to write international text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ }
+ /* If we want a compressed text chunk */
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
+ {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+ /* Write compressed chunk */
+ png_write_zTXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, 0,
+ info_ptr->text[i].compression);
+#else
+ png_warning(png_ptr, "Unable to write compressed text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+ }
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+ /* Write uncompressed chunk */
+ png_write_tEXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text,
+ 0);
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+#else
+ /* Can't get here */
+ png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+ }
+ }
+#endif /* tEXt */
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ if (info_ptr->unknown_chunks_num)
+ {
+ png_unknown_chunk *up;
+
+ png_debug(5, "writing extra chunks");
+
+ for (up = info_ptr->unknown_chunks;
+ up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+ up++)
+ {
+ int keep = png_handle_as_unknown(png_ptr, up->name);
+ if (keep != PNG_HANDLE_CHUNK_NEVER &&
+ up->location && (up->location & PNG_HAVE_PLTE) &&
+ !(up->location & PNG_HAVE_IDAT) &&
+ ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+ {
+ png_write_chunk(png_ptr, up->name, up->data, up->size);
+ }
+ }
+ }
+#endif
+}
+
+/* Writes the end of the PNG file. If you don't want to write comments or
+ * time information, you can pass NULL for info. If you already wrote these
+ * in png_write_info(), do not write them again here. If you have long
+ * comments, I suggest writing them here, and compressing them.
+ */
+void PNGAPI
+png_write_end(png_structp png_ptr, png_infop info_ptr)
+{
+ png_debug(1, "in png_write_end");
+
+ if (png_ptr == NULL)
+ return;
+ if (!(png_ptr->mode & PNG_HAVE_IDAT))
+ png_error(png_ptr, "No IDATs written into file");
+
+ /* See if user wants us to write information chunks */
+ if (info_ptr != NULL)
+ {
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ int i; /* local index variable */
+#endif
+#ifdef PNG_WRITE_tIME_SUPPORTED
+ /* Check to see if user has supplied a time chunk */
+ if ((info_ptr->valid & PNG_INFO_tIME) &&
+ !(png_ptr->mode & PNG_WROTE_tIME))
+ png_write_tIME(png_ptr, &(info_ptr->mod_time));
+#endif
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ /* Loop through comment chunks */
+ for (i = 0; i < info_ptr->num_text; i++)
+ {
+ png_debug2(2, "Writing trailer text chunk %d, type %d", i,
+ info_ptr->text[i].compression);
+ /* An internationalized chunk? */
+ if (info_ptr->text[i].compression > 0)
+ {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+ /* Write international chunk */
+ png_write_iTXt(png_ptr,
+ info_ptr->text[i].compression,
+ info_ptr->text[i].key,
+ info_ptr->text[i].lang,
+ info_ptr->text[i].lang_key,
+ info_ptr->text[i].text);
+#else
+ png_warning(png_ptr, "Unable to write international text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ }
+ else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
+ {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+ /* Write compressed chunk */
+ png_write_zTXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, 0,
+ info_ptr->text[i].compression);
+#else
+ png_warning(png_ptr, "Unable to write compressed text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+ }
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+ /* Write uncompressed chunk */
+ png_write_tEXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, 0);
+#else
+ png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ }
+ }
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ if (info_ptr->unknown_chunks_num)
+ {
+ png_unknown_chunk *up;
+
+ png_debug(5, "writing extra chunks");
+
+ for (up = info_ptr->unknown_chunks;
+ up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+ up++)
+ {
+ int keep = png_handle_as_unknown(png_ptr, up->name);
+ if (keep != PNG_HANDLE_CHUNK_NEVER &&
+ up->location && (up->location & PNG_AFTER_IDAT) &&
+ ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+ {
+ png_write_chunk(png_ptr, up->name, up->data, up->size);
+ }
+ }
+ }
+#endif
+ }
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ /* Write end of PNG file */
+ png_write_IEND(png_ptr);
+ /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
+ * and restored again in libpng-1.2.30, may cause some applications that
+ * do not set png_ptr->output_flush_fn to crash. If your application
+ * experiences a problem, please try building libpng with
+ * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
+ * png-mng-implement at lists.sf.net .
+ */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
+ png_flush(png_ptr);
+# endif
+#endif
+}
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+/* "tm" structure is not supported on WindowsCE */
+void PNGAPI
+png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
+{
+ png_debug(1, "in png_convert_from_struct_tm");
+
+ ptime->year = (png_uint_16)(1900 + ttime->tm_year);
+ ptime->month = (png_byte)(ttime->tm_mon + 1);
+ ptime->day = (png_byte)ttime->tm_mday;
+ ptime->hour = (png_byte)ttime->tm_hour;
+ ptime->minute = (png_byte)ttime->tm_min;
+ ptime->second = (png_byte)ttime->tm_sec;
+}
+
+void PNGAPI
+png_convert_from_time_t(png_timep ptime, time_t ttime)
+{
+ struct tm *tbuf;
+
+ png_debug(1, "in png_convert_from_time_t");
+
+ tbuf = gmtime(&ttime);
+ png_convert_from_struct_tm(ptime, tbuf);
+}
+#endif
+
+/* Initialize png_ptr structure, and allocate any memory needed */
+png_structp PNGAPI
+png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+ return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
+ warn_fn, NULL, NULL, NULL));
+}
+
+/* Alternate initialize png_ptr structure, and allocate any memory needed */
+png_structp PNGAPI
+png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+ volatile int png_cleanup_needed = 0;
+#ifdef PNG_SETJMP_SUPPORTED
+ volatile
+#endif
+ png_structp png_ptr;
+#ifdef PNG_SETJMP_SUPPORTED
+#ifdef USE_FAR_KEYWORD
+ jmp_buf jmpbuf;
+#endif
+#endif
+ int i;
+
+ png_debug(1, "in png_create_write_struct");
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
+ (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
+#else
+ png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
+#endif /* PNG_USER_MEM_SUPPORTED */
+ if (png_ptr == NULL)
+ return (NULL);
+
+ /* Added at libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
+ png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* Applications that neglect to set up their own setjmp() and then
+ encounter a png_error() will longjmp here. Since the jmpbuf is
+ then meaningless we abort instead of returning. */
+#ifdef USE_FAR_KEYWORD
+ if (setjmp(jmpbuf))
+#else
+ if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */
+#endif
+#ifdef USE_FAR_KEYWORD
+ png_memcpy(png_jmpbuf(png_ptr), jmpbuf, png_sizeof(jmp_buf));
+#endif
+ PNG_ABORT();
+#endif
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
+#endif /* PNG_USER_MEM_SUPPORTED */
+ png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
+
+ if (user_png_ver)
+ {
+ i = 0;
+ do
+ {
+ if (user_png_ver[i] != png_libpng_ver[i])
+ png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+ } while (png_libpng_ver[i++]);
+ }
+
+ if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
+ {
+ /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
+ * we must recompile any applications that use any older library version.
+ * For versions after libpng 1.0, we will be compatible, so we need
+ * only check the first digit.
+ */
+ if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
+ (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
+ (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
+ {
+#ifdef PNG_STDIO_SUPPORTED
+ char msg[80];
+ if (user_png_ver)
+ {
+ png_snprintf(msg, 80,
+ "Application was compiled with png.h from libpng-%.20s",
+ user_png_ver);
+ png_warning(png_ptr, msg);
+ }
+ png_snprintf(msg, 80,
+ "Application is running with png.c from libpng-%.20s",
+ png_libpng_ver);
+ png_warning(png_ptr, msg);
+#endif
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ png_ptr->flags = 0;
+#endif
+ png_warning(png_ptr,
+ "Incompatible libpng version in application and library");
+ png_cleanup_needed = 1;
+ }
+ }
+
+ /* Initialize zbuf - compression buffer */
+ png_ptr->zbuf_size = PNG_ZBUF_SIZE;
+ if (!png_cleanup_needed)
+ {
+ png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr,
+ png_ptr->zbuf_size);
+ if (png_ptr->zbuf == NULL)
+ png_cleanup_needed = 1;
+ }
+ if (png_cleanup_needed)
+ {
+ /* Clean up PNG structure and deallocate any memory. */
+ png_free(png_ptr, png_ptr->zbuf);
+ png_ptr->zbuf = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)png_ptr,
+ (png_free_ptr)free_fn, (png_voidp)mem_ptr);
+#else
+ png_destroy_struct((png_voidp)png_ptr);
+#endif
+ return (NULL);
+ }
+
+ png_set_write_fn(png_ptr, NULL, NULL, NULL);
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
+ 1, NULL, NULL);
+#endif
+
+ return (png_ptr);
+}
+
+
+/* Write a few rows of image data. If the image is interlaced,
+ * either you will have to write the 7 sub images, or, if you
+ * have called png_set_interlace_handling(), you will have to
+ * "write" the image seven times.
+ */
+void PNGAPI
+png_write_rows(png_structp png_ptr, png_bytepp row,
+ png_uint_32 num_rows)
+{
+ png_uint_32 i; /* row counter */
+ png_bytepp rp; /* row pointer */
+
+ png_debug(1, "in png_write_rows");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* Loop through the rows */
+ for (i = 0, rp = row; i < num_rows; i++, rp++)
+ {
+ png_write_row(png_ptr, *rp);
+ }
+}
+
+/* Write the image. You only need to call this function once, even
+ * if you are writing an interlaced image.
+ */
+void PNGAPI
+png_write_image(png_structp png_ptr, png_bytepp image)
+{
+ png_uint_32 i; /* row index */
+ int pass, num_pass; /* pass variables */
+ png_bytepp rp; /* points to current row */
+
+ if (png_ptr == NULL)
+ return;
+
+ png_debug(1, "in png_write_image");
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Initialize interlace handling. If image is not interlaced,
+ * this will set pass to 1
+ */
+ num_pass = png_set_interlace_handling(png_ptr);
+#else
+ num_pass = 1;
+#endif
+ /* Loop through passes */
+ for (pass = 0; pass < num_pass; pass++)
+ {
+ /* Loop through image */
+ for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
+ {
+ png_write_row(png_ptr, *rp);
+ }
+ }
+}
+
+/* Called by user to write a row of image data */
+void PNGAPI
+png_write_row(png_structp png_ptr, png_bytep row)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_debug2(1, "in png_write_row (row %ld, pass %d)",
+ png_ptr->row_number, png_ptr->pass);
+
+ /* Initialize transformations and other stuff if first time */
+ if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+ {
+ /* Make sure we wrote the header info */
+ if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
+ png_error(png_ptr,
+ "png_write_info was never called before png_write_row");
+
+ /* Check for transforms that have been set but were defined out */
+#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
+ if (png_ptr->transformations & PNG_INVERT_MONO)
+ png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
+ if (png_ptr->transformations & PNG_FILLER)
+ png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
+ defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ png_warning(png_ptr,
+ "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACK)
+ png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
+ if (png_ptr->transformations & PNG_SHIFT)
+ png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
+ if (png_ptr->transformations & PNG_BGR)
+ png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_SWAP_BYTES)
+ png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
+#endif
+
+ png_write_start_row(png_ptr);
+ }
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* If interlaced and not interested in row, return */
+ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+ {
+ switch (png_ptr->pass)
+ {
+ case 0:
+ if (png_ptr->row_number & 0x07)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 1:
+ if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 2:
+ if ((png_ptr->row_number & 0x07) != 4)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 3:
+ if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 4:
+ if ((png_ptr->row_number & 0x03) != 2)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 5:
+ if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 6:
+ if (!(png_ptr->row_number & 0x01))
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ }
+ }
+#endif
+
+ /* Set up row info for transformations */
+ png_ptr->row_info.color_type = png_ptr->color_type;
+ png_ptr->row_info.width = png_ptr->usr_width;
+ png_ptr->row_info.channels = png_ptr->usr_channels;
+ png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
+ png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
+ png_ptr->row_info.channels);
+
+ png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
+ png_ptr->row_info.width);
+
+ png_debug1(3, "row_info->color_type = %d", png_ptr->row_info.color_type);
+ png_debug1(3, "row_info->width = %lu", png_ptr->row_info.width);
+ png_debug1(3, "row_info->channels = %d", png_ptr->row_info.channels);
+ png_debug1(3, "row_info->bit_depth = %d", png_ptr->row_info.bit_depth);
+ png_debug1(3, "row_info->pixel_depth = %d", png_ptr->row_info.pixel_depth);
+ png_debug1(3, "row_info->rowbytes = %lu", png_ptr->row_info.rowbytes);
+
+ /* Copy user's row into buffer, leaving room for filter byte. */
+ png_memcpy(png_ptr->row_buf + 1, row, png_ptr->row_info.rowbytes);
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Handle interlacing */
+ if (png_ptr->interlaced && png_ptr->pass < 6 &&
+ (png_ptr->transformations & PNG_INTERLACE))
+ {
+ png_do_write_interlace(&(png_ptr->row_info),
+ png_ptr->row_buf + 1, png_ptr->pass);
+ /* This should always get caught above, but still ... */
+ if (!(png_ptr->row_info.width))
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ }
+#endif
+
+ /* Handle other transformations */
+ if (png_ptr->transformations)
+ png_do_write_transformations(png_ptr);
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ /* Write filter_method 64 (intrapixel differencing) only if
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+ * 2. Libpng did not write a PNG signature (this filter_method is only
+ * used in PNG datastreams that are embedded in MNG datastreams) and
+ * 3. The application called png_permit_mng_features with a mask that
+ * included PNG_FLAG_MNG_FILTER_64 and
+ * 4. The filter_method is 64 and
+ * 5. The color_type is RGB or RGBA
+ */
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+ (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+ {
+ /* Intrapixel differencing */
+ png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
+ }
+#endif
+
+ /* Find a filter if necessary, filter the row and write it out. */
+ png_write_find_filter(png_ptr, &(png_ptr->row_info));
+
+ if (png_ptr->write_row_fn != NULL)
+ (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+}
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+/* Set the automatic flush interval or 0 to turn flushing off */
+void PNGAPI
+png_set_flush(png_structp png_ptr, int nrows)
+{
+ png_debug(1, "in png_set_flush");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
+}
+
+/* Flush the current output buffers now */
+void PNGAPI
+png_write_flush(png_structp png_ptr)
+{
+ int wrote_IDAT;
+
+ png_debug(1, "in png_write_flush");
+
+ if (png_ptr == NULL)
+ return;
+ /* We have already written out all of the data */
+ if (png_ptr->row_number >= png_ptr->num_rows)
+ return;
+
+ do
+ {
+ int ret;
+
+ /* Compress the data */
+ ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
+ wrote_IDAT = 0;
+
+ /* Check for compression errors */
+ if (ret != Z_OK)
+ {
+ if (png_ptr->zstream.msg != NULL)
+ png_error(png_ptr, png_ptr->zstream.msg);
+ else
+ png_error(png_ptr, "zlib error");
+ }
+
+ if (!(png_ptr->zstream.avail_out))
+ {
+ /* Write the IDAT and reset the zlib output buffer */
+ png_write_IDAT(png_ptr, png_ptr->zbuf,
+ png_ptr->zbuf_size);
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ wrote_IDAT = 1;
+ }
+ } while(wrote_IDAT == 1);
+
+ /* If there is any data left to be output, write it into a new IDAT */
+ if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
+ {
+ /* Write the IDAT and reset the zlib output buffer */
+ png_write_IDAT(png_ptr, png_ptr->zbuf,
+ png_ptr->zbuf_size - png_ptr->zstream.avail_out);
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ }
+ png_ptr->flush_rows = 0;
+ png_flush(png_ptr);
+}
+#endif /* PNG_WRITE_FLUSH_SUPPORTED */
+
+/* Free all memory used by the write */
+void PNGAPI
+png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
+{
+ png_structp png_ptr = NULL;
+ png_infop info_ptr = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_free_ptr free_fn = NULL;
+ png_voidp mem_ptr = NULL;
+#endif
+
+ png_debug(1, "in png_destroy_write_struct");
+
+ if (png_ptr_ptr != NULL)
+ {
+ png_ptr = *png_ptr_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ free_fn = png_ptr->free_fn;
+ mem_ptr = png_ptr->mem_ptr;
+#endif
+ }
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (png_ptr != NULL)
+ {
+ free_fn = png_ptr->free_fn;
+ mem_ptr = png_ptr->mem_ptr;
+ }
+#endif
+
+ if (info_ptr_ptr != NULL)
+ info_ptr = *info_ptr_ptr;
+
+ if (info_ptr != NULL)
+ {
+ if (png_ptr != NULL)
+ {
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ if (png_ptr->num_chunk_list)
+ {
+ png_free(png_ptr, png_ptr->chunk_list);
+ png_ptr->num_chunk_list = 0;
+ }
+#endif
+ }
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
+ (png_voidp)mem_ptr);
+#else
+ png_destroy_struct((png_voidp)info_ptr);
+#endif
+ *info_ptr_ptr = NULL;
+ }
+
+ if (png_ptr != NULL)
+ {
+ png_write_destroy(png_ptr);
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
+ (png_voidp)mem_ptr);
+#else
+ png_destroy_struct((png_voidp)png_ptr);
+#endif
+ *png_ptr_ptr = NULL;
+ }
+}
+
+
+/* Free any memory used in png_ptr struct (old method) */
+void /* PRIVATE */
+png_write_destroy(png_structp png_ptr)
+{
+#ifdef PNG_SETJMP_SUPPORTED
+ jmp_buf tmp_jmp; /* Save jump buffer */
+#endif
+ png_error_ptr error_fn;
+ png_error_ptr warning_fn;
+ png_voidp error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_free_ptr free_fn;
+#endif
+
+ png_debug(1, "in png_write_destroy");
+
+ /* Free any memory zlib uses */
+ deflateEnd(&png_ptr->zstream);
+
+ /* Free our memory. png_free checks NULL for us. */
+ png_free(png_ptr, png_ptr->zbuf);
+ png_free(png_ptr, png_ptr->row_buf);
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ png_free(png_ptr, png_ptr->prev_row);
+ png_free(png_ptr, png_ptr->sub_row);
+ png_free(png_ptr, png_ptr->up_row);
+ png_free(png_ptr, png_ptr->avg_row);
+ png_free(png_ptr, png_ptr->paeth_row);
+#endif
+
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+ png_free(png_ptr, png_ptr->time_buffer);
+#endif
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ png_free(png_ptr, png_ptr->prev_filters);
+ png_free(png_ptr, png_ptr->filter_weights);
+ png_free(png_ptr, png_ptr->inv_filter_weights);
+ png_free(png_ptr, png_ptr->filter_costs);
+ png_free(png_ptr, png_ptr->inv_filter_costs);
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+ /* Reset structure */
+ png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
+#endif
+
+ error_fn = png_ptr->error_fn;
+ warning_fn = png_ptr->warning_fn;
+ error_ptr = png_ptr->error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ free_fn = png_ptr->free_fn;
+#endif
+
+ png_memset(png_ptr, 0, png_sizeof(png_struct));
+
+ png_ptr->error_fn = error_fn;
+ png_ptr->warning_fn = warning_fn;
+ png_ptr->error_ptr = error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_ptr->free_fn = free_fn;
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+ png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
+#endif
+}
+
+/* Allow the application to select one or more row filters to use. */
+void PNGAPI
+png_set_filter(png_structp png_ptr, int method, int filters)
+{
+ png_debug(1, "in png_set_filter");
+
+ if (png_ptr == NULL)
+ return;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+ (method == PNG_INTRAPIXEL_DIFFERENCING))
+ method = PNG_FILTER_TYPE_BASE;
+#endif
+ if (method == PNG_FILTER_TYPE_BASE)
+ {
+ switch (filters & (PNG_ALL_FILTERS | 0x07))
+ {
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ case 5:
+ case 6:
+ case 7: png_warning(png_ptr, "Unknown row filter for method 0");
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+ case PNG_FILTER_VALUE_NONE:
+ png_ptr->do_filter = PNG_FILTER_NONE; break;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ case PNG_FILTER_VALUE_SUB:
+ png_ptr->do_filter = PNG_FILTER_SUB; break;
+ case PNG_FILTER_VALUE_UP:
+ png_ptr->do_filter = PNG_FILTER_UP; break;
+ case PNG_FILTER_VALUE_AVG:
+ png_ptr->do_filter = PNG_FILTER_AVG; break;
+ case PNG_FILTER_VALUE_PAETH:
+ png_ptr->do_filter = PNG_FILTER_PAETH; break;
+ default: png_ptr->do_filter = (png_byte)filters; break;
+#else
+ default: png_warning(png_ptr, "Unknown row filter for method 0");
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+ }
+
+ /* If we have allocated the row_buf, this means we have already started
+ * with the image and we should have allocated all of the filter buffers
+ * that have been selected. If prev_row isn't already allocated, then
+ * it is too late to start using the filters that need it, since we
+ * will be missing the data in the previous row. If an application
+ * wants to start and stop using particular filters during compression,
+ * it should start out with all of the filters, and then add and
+ * remove them after the start of compression.
+ */
+ if (png_ptr->row_buf != NULL)
+ {
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
+ {
+ png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
+ (png_ptr->rowbytes + 1));
+ png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
+ }
+
+ if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
+ {
+ if (png_ptr->prev_row == NULL)
+ {
+ png_warning(png_ptr, "Can't add Up filter after starting");
+ png_ptr->do_filter &= ~PNG_FILTER_UP;
+ }
+ else
+ {
+ png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
+ (png_ptr->rowbytes + 1));
+ png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
+ }
+ }
+
+ if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
+ {
+ if (png_ptr->prev_row == NULL)
+ {
+ png_warning(png_ptr, "Can't add Average filter after starting");
+ png_ptr->do_filter &= ~PNG_FILTER_AVG;
+ }
+ else
+ {
+ png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
+ (png_ptr->rowbytes + 1));
+ png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
+ }
+ }
+
+ if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
+ png_ptr->paeth_row == NULL)
+ {
+ if (png_ptr->prev_row == NULL)
+ {
+ png_warning(png_ptr, "Can't add Paeth filter after starting");
+ png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
+ }
+ else
+ {
+ png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
+ (png_ptr->rowbytes + 1));
+ png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
+ }
+ }
+
+ if (png_ptr->do_filter == PNG_NO_FILTERS)
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+ png_ptr->do_filter = PNG_FILTER_NONE;
+ }
+ }
+ else
+ png_error(png_ptr, "Unknown custom filter method");
+}
+
+/* This allows us to influence the way in which libpng chooses the "best"
+ * filter for the current scanline. While the "minimum-sum-of-absolute-
+ * differences metric is relatively fast and effective, there is some
+ * question as to whether it can be improved upon by trying to keep the
+ * filtered data going to zlib more consistent, hopefully resulting in
+ * better compression.
+ */
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */
+void PNGAPI
+png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
+ int num_weights, png_doublep filter_weights,
+ png_doublep filter_costs)
+{
+ int i;
+
+ png_debug(1, "in png_set_filter_heuristics");
+
+ if (png_ptr == NULL)
+ return;
+ if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
+ {
+ png_warning(png_ptr, "Unknown filter heuristic method");
+ return;
+ }
+
+ if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
+ {
+ heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
+ }
+
+ if (num_weights < 0 || filter_weights == NULL ||
+ heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
+ {
+ num_weights = 0;
+ }
+
+ png_ptr->num_prev_filters = (png_byte)num_weights;
+ png_ptr->heuristic_method = (png_byte)heuristic_method;
+
+ if (num_weights > 0)
+ {
+ if (png_ptr->prev_filters == NULL)
+ {
+ png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(png_sizeof(png_byte) * num_weights));
+
+ /* To make sure that the weighting starts out fairly */
+ for (i = 0; i < num_weights; i++)
+ {
+ png_ptr->prev_filters[i] = 255;
+ }
+ }
+
+ if (png_ptr->filter_weights == NULL)
+ {
+ png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+
+ png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+ for (i = 0; i < num_weights; i++)
+ {
+ png_ptr->inv_filter_weights[i] =
+ png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
+ }
+ }
+
+ for (i = 0; i < num_weights; i++)
+ {
+ if (filter_weights[i] < 0.0)
+ {
+ png_ptr->inv_filter_weights[i] =
+ png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
+ }
+ else
+ {
+ png_ptr->inv_filter_weights[i] =
+ (png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
+ png_ptr->filter_weights[i] =
+ (png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
+ }
+ }
+ }
+
+ /* If, in the future, there are other filter methods, this would
+ * need to be based on png_ptr->filter.
+ */
+ if (png_ptr->filter_costs == NULL)
+ {
+ png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+
+ png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+
+ for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
+ {
+ png_ptr->inv_filter_costs[i] =
+ png_ptr->filter_costs[i] = PNG_COST_FACTOR;
+ }
+ }
+
+ /* Here is where we set the relative costs of the different filters. We
+ * should take the desired compression level into account when setting
+ * the costs, so that Paeth, for instance, has a high relative cost at low
+ * compression levels, while it has a lower relative cost at higher
+ * compression settings. The filter types are in order of increasing
+ * relative cost, so it would be possible to do this with an algorithm.
+ */
+ for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
+ {
+ if (filter_costs == NULL || filter_costs[i] < 0.0)
+ {
+ png_ptr->inv_filter_costs[i] =
+ png_ptr->filter_costs[i] = PNG_COST_FACTOR;
+ }
+ else if (filter_costs[i] >= 1.0)
+ {
+ png_ptr->inv_filter_costs[i] =
+ (png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
+ png_ptr->filter_costs[i] =
+ (png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
+ }
+ }
+}
+#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+
+void PNGAPI
+png_set_compression_level(png_structp png_ptr, int level)
+{
+ png_debug(1, "in png_set_compression_level");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
+ png_ptr->zlib_level = level;
+}
+
+void PNGAPI
+png_set_compression_mem_level(png_structp png_ptr, int mem_level)
+{
+ png_debug(1, "in png_set_compression_mem_level");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
+ png_ptr->zlib_mem_level = mem_level;
+}
+
+void PNGAPI
+png_set_compression_strategy(png_structp png_ptr, int strategy)
+{
+ png_debug(1, "in png_set_compression_strategy");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
+ png_ptr->zlib_strategy = strategy;
+}
+
+void PNGAPI
+png_set_compression_window_bits(png_structp png_ptr, int window_bits)
+{
+ if (png_ptr == NULL)
+ return;
+ if (window_bits > 15)
+ png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+ else if (window_bits < 8)
+ png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+#ifndef WBITS_8_OK
+ /* Avoid libpng bug with 256-byte windows */
+ if (window_bits == 8)
+ {
+ png_warning(png_ptr, "Compression window is being reset to 512");
+ window_bits = 9;
+ }
+#endif
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
+ png_ptr->zlib_window_bits = window_bits;
+}
+
+void PNGAPI
+png_set_compression_method(png_structp png_ptr, int method)
+{
+ png_debug(1, "in png_set_compression_method");
+
+ if (png_ptr == NULL)
+ return;
+ if (method != 8)
+ png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
+ png_ptr->zlib_method = method;
+}
+
+void PNGAPI
+png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
+{
+ if (png_ptr == NULL)
+ return;
+ png_ptr->write_row_fn = write_row_fn;
+}
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+void PNGAPI
+png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
+ write_user_transform_fn)
+{
+ png_debug(1, "in png_set_write_user_transform_fn");
+
+ if (png_ptr == NULL)
+ return;
+ png_ptr->transformations |= PNG_USER_TRANSFORM;
+ png_ptr->write_user_transform_fn = write_user_transform_fn;
+}
+#endif
+
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_write_png(png_structp png_ptr, png_infop info_ptr,
+ int transforms, voidp params)
+{
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* Write the file header information. */
+ png_write_info(png_ptr, info_ptr);
+
+ /* ------ these transformations don't touch the info structure ------- */
+
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+ /* Invert monochrome pixels */
+ if (transforms & PNG_TRANSFORM_INVERT_MONO)
+ png_set_invert_mono(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+ /* Shift the pixels up to a legal bit depth and fill in
+ * as appropriate to correctly scale the image.
+ */
+ if ((transforms & PNG_TRANSFORM_SHIFT)
+ && (info_ptr->valid & PNG_INFO_sBIT))
+ png_set_shift(png_ptr, &info_ptr->sig_bit);
+#endif
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+ /* Pack pixels into bytes */
+ if (transforms & PNG_TRANSFORM_PACKING)
+ png_set_packing(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+ /* Swap location of alpha bytes from ARGB to RGBA */
+ if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+ png_set_swap_alpha(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+ /* Pack XRGB/RGBX/ARGB/RGBA into * RGB (4 channels -> 3 channels) */
+ if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
+ png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
+ else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
+ png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+#endif
+
+#ifdef PNG_WRITE_BGR_SUPPORTED
+ /* Flip BGR pixels to RGB */
+ if (transforms & PNG_TRANSFORM_BGR)
+ png_set_bgr(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+ /* Swap bytes of 16-bit files to most significant byte first */
+ if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+ png_set_swap(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+ /* Swap bits of 1, 2, 4 bit packed pixel formats */
+ if (transforms & PNG_TRANSFORM_PACKSWAP)
+ png_set_packswap(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ /* Invert the alpha channel from opacity to transparency */
+ if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+ png_set_invert_alpha(png_ptr);
+#endif
+
+ /* ----------------------- end of transformations ------------------- */
+
+ /* Write the bits */
+ if (info_ptr->valid & PNG_INFO_IDAT)
+ png_write_image(png_ptr, info_ptr->row_pointers);
+
+ /* It is REQUIRED to call this to finish writing the rest of the file */
+ png_write_end(png_ptr, info_ptr);
+
+ transforms = transforms; /* Quiet compiler warnings */
+ params = params;
+}
+#endif
+#endif /* PNG_WRITE_SUPPORTED */
--- /dev/null
+
+/* pngwtran.c - transforms the data in a row for PNG writers
+ *
+ * Last changed in libpng 1.4.1 [February 25, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#ifdef PNG_WRITE_SUPPORTED
+#include "pngpriv.h"
+
+/* Transform the data according to the user's wishes. The order of
+ * transformations is significant.
+ */
+void /* PRIVATE */
+png_do_write_transformations(png_structp png_ptr)
+{
+ png_debug(1, "in png_do_write_transformations");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+ if (png_ptr->transformations & PNG_USER_TRANSFORM)
+ if (png_ptr->write_user_transform_fn != NULL)
+ (*(png_ptr->write_user_transform_fn)) /* User write transform
+ function */
+ (png_ptr, /* png_ptr */
+ &(png_ptr->row_info), /* row_info: */
+ /* png_uint_32 width; width of row */
+ /* png_uint_32 rowbytes; number of bytes in row */
+ /* png_byte color_type; color type of pixels */
+ /* png_byte bit_depth; bit depth of samples */
+ /* png_byte channels; number of channels (1-4) */
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */
+ png_ptr->row_buf + 1); /* start of pixel data for row */
+#endif
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+ if (png_ptr->transformations & PNG_FILLER)
+ png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ png_ptr->flags);
+#endif
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_WRITE_PACK_SUPPORTED
+ if (png_ptr->transformations & PNG_PACK)
+ png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ (png_uint_32)png_ptr->bit_depth);
+#endif
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_SWAP_BYTES)
+ png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+ if (png_ptr->transformations & PNG_SHIFT)
+ png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ &(png_ptr->shift));
+#endif
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+ if (png_ptr->transformations & PNG_SWAP_ALPHA)
+ png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ if (png_ptr->transformations & PNG_INVERT_ALPHA)
+ png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_WRITE_BGR_SUPPORTED
+ if (png_ptr->transformations & PNG_BGR)
+ png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+ if (png_ptr->transformations & PNG_INVERT_MONO)
+ png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+}
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The
+ * row_info bit depth should be 8 (one pixel per byte). The channels
+ * should be 1 (this only happens on grayscale and paletted images).
+ */
+void /* PRIVATE */
+png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
+{
+ png_debug(1, "in png_do_pack");
+
+ if (row_info->bit_depth == 8 &&
+ row_info->channels == 1)
+ {
+ switch ((int)bit_depth)
+ {
+ case 1:
+ {
+ png_bytep sp, dp;
+ int mask, v;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ sp = row;
+ dp = row;
+ mask = 0x80;
+ v = 0;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (*sp != 0)
+ v |= mask;
+ sp++;
+ if (mask > 1)
+ mask >>= 1;
+ else
+ {
+ mask = 0x80;
+ *dp = (png_byte)v;
+ dp++;
+ v = 0;
+ }
+ }
+ if (mask != 0x80)
+ *dp = (png_byte)v;
+ break;
+ }
+ case 2:
+ {
+ png_bytep sp, dp;
+ int shift, v;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ sp = row;
+ dp = row;
+ shift = 6;
+ v = 0;
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte value;
+
+ value = (png_byte)(*sp & 0x03);
+ v |= (value << shift);
+ if (shift == 0)
+ {
+ shift = 6;
+ *dp = (png_byte)v;
+ dp++;
+ v = 0;
+ }
+ else
+ shift -= 2;
+ sp++;
+ }
+ if (shift != 6)
+ *dp = (png_byte)v;
+ break;
+ }
+ case 4:
+ {
+ png_bytep sp, dp;
+ int shift, v;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ sp = row;
+ dp = row;
+ shift = 4;
+ v = 0;
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte value;
+
+ value = (png_byte)(*sp & 0x0f);
+ v |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 4;
+ *dp = (png_byte)v;
+ dp++;
+ v = 0;
+ }
+ else
+ shift -= 4;
+
+ sp++;
+ }
+ if (shift != 4)
+ *dp = (png_byte)v;
+ break;
+ }
+ }
+ row_info->bit_depth = (png_byte)bit_depth;
+ row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_info->width);
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+/* Shift pixel values to take advantage of whole range. Pass the
+ * true number of bits in bit_depth. The row should be packed
+ * according to row_info->bit_depth. Thus, if you had a row of
+ * bit depth 4, but the pixels only had values from 0 to 7, you
+ * would pass 3 as bit_depth, and this routine would translate the
+ * data to 0 to 15.
+ */
+void /* PRIVATE */
+png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
+{
+ png_debug(1, "in png_do_shift");
+
+ if (
+ row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ int shift_start[4], shift_dec[4];
+ int channels = 0;
+
+ if (row_info->color_type & PNG_COLOR_MASK_COLOR)
+ {
+ shift_start[channels] = row_info->bit_depth - bit_depth->red;
+ shift_dec[channels] = bit_depth->red;
+ channels++;
+ shift_start[channels] = row_info->bit_depth - bit_depth->green;
+ shift_dec[channels] = bit_depth->green;
+ channels++;
+ shift_start[channels] = row_info->bit_depth - bit_depth->blue;
+ shift_dec[channels] = bit_depth->blue;
+ channels++;
+ }
+ else
+ {
+ shift_start[channels] = row_info->bit_depth - bit_depth->gray;
+ shift_dec[channels] = bit_depth->gray;
+ channels++;
+ }
+ if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
+ {
+ shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
+ shift_dec[channels] = bit_depth->alpha;
+ channels++;
+ }
+
+ /* With low row depths, could only be grayscale, so one channel */
+ if (row_info->bit_depth < 8)
+ {
+ png_bytep bp = row;
+ png_uint_32 i;
+ png_byte mask;
+ png_uint_32 row_bytes = row_info->rowbytes;
+
+ if (bit_depth->gray == 1 && row_info->bit_depth == 2)
+ mask = 0x55;
+ else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
+ mask = 0x11;
+ else
+ mask = 0xff;
+
+ for (i = 0; i < row_bytes; i++, bp++)
+ {
+ png_uint_16 v;
+ int j;
+
+ v = *bp;
+ *bp = 0;
+ for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
+ {
+ if (j > 0)
+ *bp |= (png_byte)((v << j) & 0xff);
+ else
+ *bp |= (png_byte)((v >> (-j)) & mask);
+ }
+ }
+ }
+ else if (row_info->bit_depth == 8)
+ {
+ png_bytep bp = row;
+ png_uint_32 i;
+ png_uint_32 istop = channels * row_info->width;
+
+ for (i = 0; i < istop; i++, bp++)
+ {
+
+ png_uint_16 v;
+ int j;
+ int c = (int)(i%channels);
+
+ v = *bp;
+ *bp = 0;
+ for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+ {
+ if (j > 0)
+ *bp |= (png_byte)((v << j) & 0xff);
+ else
+ *bp |= (png_byte)((v >> (-j)) & 0xff);
+ }
+ }
+ }
+ else
+ {
+ png_bytep bp;
+ png_uint_32 i;
+ png_uint_32 istop = channels * row_info->width;
+
+ for (bp = row, i = 0; i < istop; i++)
+ {
+ int c = (int)(i%channels);
+ png_uint_16 value, v;
+ int j;
+
+ v = (png_uint_16)(((png_uint_16)(*bp) << 8) + *(bp + 1));
+ value = 0;
+ for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+ {
+ if (j > 0)
+ value |= (png_uint_16)((v << j) & (png_uint_16)0xffff);
+ else
+ value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);
+ }
+ *bp++ = (png_byte)(value >> 8);
+ *bp++ = (png_byte)(value & 0xff);
+ }
+ }
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+void /* PRIVATE */
+png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_write_swap_alpha");
+
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ /* This converts from ARGB to RGBA */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save;
+ }
+ }
+ /* This converts from AARRGGBB to RRGGBBAA */
+ else
+ {
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save[2];
+ save[0] = *(sp++);
+ save[1] = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save[0];
+ *(dp++) = save[1];
+ }
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ /* This converts from AG to GA */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save;
+ }
+ }
+ /* This converts from AAGG to GGAA */
+ else
+ {
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save[2];
+ save[0] = *(sp++);
+ save[1] = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save[0];
+ *(dp++) = save[1];
+ }
+ }
+ }
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+void /* PRIVATE */
+png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_write_invert_alpha");
+
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ /* This inverts the alpha channel in RGBA */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ /* Does nothing
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ */
+ sp+=3; dp = sp;
+ *(dp++) = (png_byte)(255 - *(sp++));
+ }
+ }
+ /* This inverts the alpha channel in RRGGBBAA */
+ else
+ {
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ /* Does nothing
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ */
+ sp+=6; dp = sp;
+ *(dp++) = (png_byte)(255 - *(sp++));
+ *(dp++) = (png_byte)(255 - *(sp++));
+ }
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ /* This inverts the alpha channel in GA */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ *(dp++) = *(sp++);
+ *(dp++) = (png_byte)(255 - *(sp++));
+ }
+ }
+ /* This inverts the alpha channel in GGAA */
+ else
+ {
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ /* Does nothing
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ */
+ sp+=2; dp = sp;
+ *(dp++) = (png_byte)(255 - *(sp++));
+ *(dp++) = (png_byte)(255 - *(sp++));
+ }
+ }
+ }
+ }
+}
+#endif
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Undoes intrapixel differencing */
+void /* PRIVATE */
+png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_write_intrapixel");
+
+ if (
+ (row_info->color_type & PNG_COLOR_MASK_COLOR))
+ {
+ int bytes_per_pixel;
+ png_uint_32 row_width = row_info->width;
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 3;
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 4;
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ *(rp) = (png_byte)((*rp - *(rp+1))&0xff);
+ *(rp+2) = (png_byte)((*(rp+2) - *(rp+1))&0xff);
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 6;
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 8;
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ png_uint_32 s0 = (*(rp ) << 8) | *(rp+1);
+ png_uint_32 s1 = (*(rp+2) << 8) | *(rp+3);
+ png_uint_32 s2 = (*(rp+4) << 8) | *(rp+5);
+ png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL);
+ png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
+ *(rp ) = (png_byte)((red >> 8) & 0xff);
+ *(rp+1) = (png_byte)(red & 0xff);
+ *(rp+4) = (png_byte)((blue >> 8) & 0xff);
+ *(rp+5) = (png_byte)(blue & 0xff);
+ }
+ }
+ }
+}
+#endif /* PNG_MNG_FEATURES_SUPPORTED */
+#endif /* PNG_WRITE_SUPPORTED */
--- /dev/null
+
+/* pngwutil.c - utilities to write a PNG file
+ *
+ * Last changed in libpng 1.4.1 [February 25, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#define PNG_NO_PEDANTIC_WARNINGS
+#include "png.h"
+#ifdef PNG_WRITE_SUPPORTED
+#include "pngpriv.h"
+
+/* Place a 32-bit number into a buffer in PNG byte order. We work
+ * with unsigned numbers for convenience, although one supported
+ * ancillary chunk uses signed (two's complement) numbers.
+ */
+void PNGAPI
+png_save_uint_32(png_bytep buf, png_uint_32 i)
+{
+ buf[0] = (png_byte)((i >> 24) & 0xff);
+ buf[1] = (png_byte)((i >> 16) & 0xff);
+ buf[2] = (png_byte)((i >> 8) & 0xff);
+ buf[3] = (png_byte)(i & 0xff);
+}
+
+#ifdef PNG_SAVE_INT_32_SUPPORTED
+/* The png_save_int_32 function assumes integers are stored in two's
+ * complement format. If this isn't the case, then this routine needs to
+ * be modified to write data in two's complement format.
+ */
+void PNGAPI
+png_save_int_32(png_bytep buf, png_int_32 i)
+{
+ buf[0] = (png_byte)((i >> 24) & 0xff);
+ buf[1] = (png_byte)((i >> 16) & 0xff);
+ buf[2] = (png_byte)((i >> 8) & 0xff);
+ buf[3] = (png_byte)(i & 0xff);
+}
+#endif
+
+/* Place a 16-bit number into a buffer in PNG byte order.
+ * The parameter is declared unsigned int, not png_uint_16,
+ * just to avoid potential problems on pre-ANSI C compilers.
+ */
+void PNGAPI
+png_save_uint_16(png_bytep buf, unsigned int i)
+{
+ buf[0] = (png_byte)((i >> 8) & 0xff);
+ buf[1] = (png_byte)(i & 0xff);
+}
+
+/* Simple function to write the signature. If we have already written
+ * the magic bytes of the signature, or more likely, the PNG stream is
+ * being embedded into another stream and doesn't need its own signature,
+ * we should call png_set_sig_bytes() to tell libpng how many of the
+ * bytes have already been written.
+ */
+void PNGAPI
+png_write_sig(png_structp png_ptr)
+{
+ png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the signature is being written */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
+#endif
+
+ /* Write the rest of the 8 byte signature */
+ png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
+ (png_size_t)(8 - png_ptr->sig_bytes));
+ if (png_ptr->sig_bytes < 3)
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+
+/* Write a PNG chunk all at once. The type is an array of ASCII characters
+ * representing the chunk name. The array must be at least 4 bytes in
+ * length, and does not need to be null terminated. To be safe, pass the
+ * pre-defined chunk names here, and if you need a new one, define it
+ * where the others are defined. The length is the length of the data.
+ * All the data must be present. If that is not possible, use the
+ * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
+ * functions instead.
+ */
+void PNGAPI
+png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
+ png_bytep data, png_size_t length)
+{
+ if (png_ptr == NULL)
+ return;
+ png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
+ png_write_chunk_data(png_ptr, data, (png_size_t)length);
+ png_write_chunk_end(png_ptr);
+}
+
+/* Write the start of a PNG chunk. The type is the chunk type.
+ * The total_length is the sum of the lengths of all the data you will be
+ * passing in png_write_chunk_data().
+ */
+void PNGAPI
+png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
+ png_uint_32 length)
+{
+ png_byte buf[8];
+
+ png_debug2(0, "Writing %s chunk, length = %lu", chunk_name,
+ (unsigned long)length);
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the chunk header is being written.
+ * PNG_IO_CHUNK_HDR requires a single I/O call.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
+#endif
+
+ /* Write the length and the chunk name */
+ png_save_uint_32(buf, length);
+ png_memcpy(buf + 4, chunk_name, 4);
+ png_write_data(png_ptr, buf, (png_size_t)8);
+ /* Put the chunk name into png_ptr->chunk_name */
+ png_memcpy(png_ptr->chunk_name, chunk_name, 4);
+ /* Reset the crc and run it over the chunk name */
+ png_reset_crc(png_ptr);
+ png_calculate_crc(png_ptr, chunk_name, 4);
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that chunk data will (possibly) be written.
+ * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
+#endif
+}
+
+/* Write the data of a PNG chunk started with png_write_chunk_start().
+ * Note that multiple calls to this function are allowed, and that the
+ * sum of the lengths from these calls *must* add up to the total_length
+ * given to png_write_chunk_start().
+ */
+void PNGAPI
+png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+ /* Write the data, and run the CRC over it */
+ if (png_ptr == NULL)
+ return;
+ if (data != NULL && length > 0)
+ {
+ png_write_data(png_ptr, data, length);
+ /* Update the CRC after writing the data,
+ * in case that the user I/O routine alters it.
+ */
+ png_calculate_crc(png_ptr, data, length);
+ }
+}
+
+/* Finish a chunk started with png_write_chunk_start(). */
+void PNGAPI
+png_write_chunk_end(png_structp png_ptr)
+{
+ png_byte buf[4];
+
+ if (png_ptr == NULL) return;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the chunk CRC is being written.
+ * PNG_IO_CHUNK_CRC requires a single I/O function call.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
+#endif
+
+ /* Write the crc in a single operation */
+ png_save_uint_32(buf, png_ptr->crc);
+
+ png_write_data(png_ptr, buf, (png_size_t)4);
+}
+
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
+/* This pair of functions encapsulates the operation of (a) compressing a
+ * text string, and (b) issuing it later as a series of chunk data writes.
+ * The compression_state structure is shared context for these functions
+ * set up by the caller in order to make the whole mess thread-safe.
+ */
+
+typedef struct
+{
+ char *input; /* The uncompressed input data */
+ int input_len; /* Its length */
+ int num_output_ptr; /* Number of output pointers used */
+ int max_output_ptr; /* Size of output_ptr */
+ png_charpp output_ptr; /* Array of pointers to output */
+} compression_state;
+
+/* Compress given text into storage in the png_ptr structure */
+static int /* PRIVATE */
+png_text_compress(png_structp png_ptr,
+ png_charp text, png_size_t text_len, int compression,
+ compression_state *comp)
+{
+ int ret;
+
+ comp->num_output_ptr = 0;
+ comp->max_output_ptr = 0;
+ comp->output_ptr = NULL;
+ comp->input = NULL;
+ comp->input_len = 0;
+
+ /* We may just want to pass the text right through */
+ if (compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+ comp->input = text;
+ comp->input_len = text_len;
+ return((int)text_len);
+ }
+
+ if (compression >= PNG_TEXT_COMPRESSION_LAST)
+ {
+#ifdef PNG_STDIO_SUPPORTED
+ char msg[50];
+ png_snprintf(msg, 50, "Unknown compression type %d", compression);
+ png_warning(png_ptr, msg);
+#else
+ png_warning(png_ptr, "Unknown compression type");
+#endif
+ }
+
+ /* We can't write the chunk until we find out how much data we have,
+ * which means we need to run the compressor first and save the
+ * output. This shouldn't be a problem, as the vast majority of
+ * comments should be reasonable, but we will set up an array of
+ * malloc'd pointers to be sure.
+ *
+ * If we knew the application was well behaved, we could simplify this
+ * greatly by assuming we can always malloc an output buffer large
+ * enough to hold the compressed text ((1001 * text_len / 1000) + 12)
+ * and malloc this directly. The only time this would be a bad idea is
+ * if we can't malloc more than 64K and we have 64K of random input
+ * data, or if the input string is incredibly large (although this
+ * wouldn't cause a failure, just a slowdown due to swapping).
+ */
+
+ /* Set up the compression buffers */
+ png_ptr->zstream.avail_in = (uInt)text_len;
+ png_ptr->zstream.next_in = (Bytef *)text;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf;
+
+ /* This is the same compression loop as in png_write_row() */
+ do
+ {
+ /* Compress the data */
+ ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
+ if (ret != Z_OK)
+ {
+ /* Error */
+ if (png_ptr->zstream.msg != NULL)
+ png_error(png_ptr, png_ptr->zstream.msg);
+ else
+ png_error(png_ptr, "zlib error");
+ }
+ /* Check to see if we need more room */
+ if (!(png_ptr->zstream.avail_out))
+ {
+ /* Make sure the output array has room */
+ if (comp->num_output_ptr >= comp->max_output_ptr)
+ {
+ int old_max;
+
+ old_max = comp->max_output_ptr;
+ comp->max_output_ptr = comp->num_output_ptr + 4;
+ if (comp->output_ptr != NULL)
+ {
+ png_charpp old_ptr;
+
+ old_ptr = comp->output_ptr;
+ comp->output_ptr = (png_charpp)png_malloc(png_ptr,
+ (png_alloc_size_t)
+ (comp->max_output_ptr * png_sizeof(png_charpp)));
+ png_memcpy(comp->output_ptr, old_ptr, old_max
+ * png_sizeof(png_charp));
+ png_free(png_ptr, old_ptr);
+ }
+ else
+ comp->output_ptr = (png_charpp)png_malloc(png_ptr,
+ (png_alloc_size_t)
+ (comp->max_output_ptr * png_sizeof(png_charp)));
+ }
+
+ /* Save the data */
+ comp->output_ptr[comp->num_output_ptr] =
+ (png_charp)png_malloc(png_ptr,
+ (png_alloc_size_t)png_ptr->zbuf_size);
+ png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
+ png_ptr->zbuf_size);
+ comp->num_output_ptr++;
+
+ /* and reset the buffer */
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ }
+ /* Continue until we don't have any more to compress */
+ } while (png_ptr->zstream.avail_in);
+
+ /* Finish the compression */
+ do
+ {
+ /* Tell zlib we are finished */
+ ret = deflate(&png_ptr->zstream, Z_FINISH);
+
+ if (ret == Z_OK)
+ {
+ /* Check to see if we need more room */
+ if (!(png_ptr->zstream.avail_out))
+ {
+ /* Check to make sure our output array has room */
+ if (comp->num_output_ptr >= comp->max_output_ptr)
+ {
+ int old_max;
+
+ old_max = comp->max_output_ptr;
+ comp->max_output_ptr = comp->num_output_ptr + 4;
+ if (comp->output_ptr != NULL)
+ {
+ png_charpp old_ptr;
+
+ old_ptr = comp->output_ptr;
+ /* This could be optimized to realloc() */
+ comp->output_ptr = (png_charpp)png_malloc(png_ptr,
+ (png_alloc_size_t)(comp->max_output_ptr *
+ png_sizeof(png_charp)));
+ png_memcpy(comp->output_ptr, old_ptr,
+ old_max * png_sizeof(png_charp));
+ png_free(png_ptr, old_ptr);
+ }
+ else
+ comp->output_ptr = (png_charpp)png_malloc(png_ptr,
+ (png_alloc_size_t)(comp->max_output_ptr *
+ png_sizeof(png_charp)));
+ }
+
+ /* Save the data */
+ comp->output_ptr[comp->num_output_ptr] =
+ (png_charp)png_malloc(png_ptr,
+ (png_alloc_size_t)png_ptr->zbuf_size);
+ png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
+ png_ptr->zbuf_size);
+ comp->num_output_ptr++;
+
+ /* and reset the buffer pointers */
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ }
+ }
+ else if (ret != Z_STREAM_END)
+ {
+ /* We got an error */
+ if (png_ptr->zstream.msg != NULL)
+ png_error(png_ptr, png_ptr->zstream.msg);
+ else
+ png_error(png_ptr, "zlib error");
+ }
+ } while (ret != Z_STREAM_END);
+
+ /* Text length is number of buffers plus last buffer */
+ text_len = png_ptr->zbuf_size * comp->num_output_ptr;
+ if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
+ text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
+
+ return((int)text_len);
+}
+
+/* Ship the compressed text out via chunk writes */
+static void /* PRIVATE */
+png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
+{
+ int i;
+
+ /* Handle the no-compression case */
+ if (comp->input)
+ {
+ png_write_chunk_data(png_ptr, (png_bytep)comp->input,
+ (png_size_t)comp->input_len);
+ return;
+ }
+
+ /* Write saved output buffers, if any */
+ for (i = 0; i < comp->num_output_ptr; i++)
+ {
+ png_write_chunk_data(png_ptr, (png_bytep)comp->output_ptr[i],
+ (png_size_t)png_ptr->zbuf_size);
+ png_free(png_ptr, comp->output_ptr[i]);
+ }
+ if (comp->max_output_ptr != 0)
+ png_free(png_ptr, comp->output_ptr);
+ /* Write anything left in zbuf */
+ if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
+ png_write_chunk_data(png_ptr, png_ptr->zbuf,
+ (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
+
+ /* Reset zlib for another zTXt/iTXt or image data */
+ deflateReset(&png_ptr->zstream);
+ png_ptr->zstream.data_type = Z_BINARY;
+}
+#endif
+
+/* Write the IHDR chunk, and update the png_struct with the necessary
+ * information. Note that the rest of this code depends upon this
+ * information being correct.
+ */
+void /* PRIVATE */
+png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
+ int bit_depth, int color_type, int compression_type, int filter_type,
+ int interlace_type)
+{
+ PNG_IHDR;
+ int ret;
+
+ png_byte buf[13]; /* Buffer to store the IHDR info */
+
+ png_debug(1, "in png_write_IHDR");
+
+ /* Check that we have valid input data from the application info */
+ switch (color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ switch (bit_depth)
+ {
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+ case 16: png_ptr->channels = 1; break;
+ default: png_error(png_ptr,
+ "Invalid bit depth for grayscale image");
+ }
+ break;
+ case PNG_COLOR_TYPE_RGB:
+ if (bit_depth != 8 && bit_depth != 16)
+ png_error(png_ptr, "Invalid bit depth for RGB image");
+ png_ptr->channels = 3;
+ break;
+ case PNG_COLOR_TYPE_PALETTE:
+ switch (bit_depth)
+ {
+ case 1:
+ case 2:
+ case 4:
+ case 8: png_ptr->channels = 1; break;
+ default: png_error(png_ptr, "Invalid bit depth for paletted image");
+ }
+ break;
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ if (bit_depth != 8 && bit_depth != 16)
+ png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
+ png_ptr->channels = 2;
+ break;
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ if (bit_depth != 8 && bit_depth != 16)
+ png_error(png_ptr, "Invalid bit depth for RGBA image");
+ png_ptr->channels = 4;
+ break;
+ default:
+ png_error(png_ptr, "Invalid image color type specified");
+ }
+
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Invalid compression type specified");
+ compression_type = PNG_COMPRESSION_TYPE_BASE;
+ }
+
+ /* Write filter_method 64 (intrapixel differencing) only if
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+ * 2. Libpng did not write a PNG signature (this filter_method is only
+ * used in PNG datastreams that are embedded in MNG datastreams) and
+ * 3. The application called png_permit_mng_features with a mask that
+ * included PNG_FLAG_MNG_FILTER_64 and
+ * 4. The filter_method is 64 and
+ * 5. The color_type is RGB or RGBA
+ */
+ if (
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+ ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
+ (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
+ (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
+#endif
+ filter_type != PNG_FILTER_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Invalid filter type specified");
+ filter_type = PNG_FILTER_TYPE_BASE;
+ }
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ if (interlace_type != PNG_INTERLACE_NONE &&
+ interlace_type != PNG_INTERLACE_ADAM7)
+ {
+ png_warning(png_ptr, "Invalid interlace type specified");
+ interlace_type = PNG_INTERLACE_ADAM7;
+ }
+#else
+ interlace_type=PNG_INTERLACE_NONE;
+#endif
+
+ /* Save the relevent information */
+ png_ptr->bit_depth = (png_byte)bit_depth;
+ png_ptr->color_type = (png_byte)color_type;
+ png_ptr->interlaced = (png_byte)interlace_type;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ png_ptr->filter_type = (png_byte)filter_type;
+#endif
+ png_ptr->compression_type = (png_byte)compression_type;
+ png_ptr->width = width;
+ png_ptr->height = height;
+
+ png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
+ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
+ /* Set the usr info, so any transformations can modify it */
+ png_ptr->usr_width = png_ptr->width;
+ png_ptr->usr_bit_depth = png_ptr->bit_depth;
+ png_ptr->usr_channels = png_ptr->channels;
+
+ /* Pack the header information into the buffer */
+ png_save_uint_32(buf, width);
+ png_save_uint_32(buf + 4, height);
+ buf[8] = (png_byte)bit_depth;
+ buf[9] = (png_byte)color_type;
+ buf[10] = (png_byte)compression_type;
+ buf[11] = (png_byte)filter_type;
+ buf[12] = (png_byte)interlace_type;
+
+ /* Write the chunk */
+ png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
+
+ /* Initialize zlib with PNG info */
+ png_ptr->zstream.zalloc = png_zalloc;
+ png_ptr->zstream.zfree = png_zfree;
+ png_ptr->zstream.opaque = (voidpf)png_ptr;
+ if (!(png_ptr->do_filter))
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
+ png_ptr->bit_depth < 8)
+ png_ptr->do_filter = PNG_FILTER_NONE;
+ else
+ png_ptr->do_filter = PNG_ALL_FILTERS;
+ }
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
+ {
+ if (png_ptr->do_filter != PNG_FILTER_NONE)
+ png_ptr->zlib_strategy = Z_FILTERED;
+ else
+ png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
+ }
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
+ png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
+ png_ptr->zlib_mem_level = 8;
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
+ png_ptr->zlib_window_bits = 15;
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
+ png_ptr->zlib_method = 8;
+ ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
+ png_ptr->zlib_method, png_ptr->zlib_window_bits,
+ png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
+ if (ret != Z_OK)
+ {
+ if (ret == Z_VERSION_ERROR) png_error(png_ptr,
+ "zlib failed to initialize compressor -- version error");
+ if (ret == Z_STREAM_ERROR) png_error(png_ptr,
+ "zlib failed to initialize compressor -- stream error");
+ if (ret == Z_MEM_ERROR) png_error(png_ptr,
+ "zlib failed to initialize compressor -- mem error");
+ png_error(png_ptr, "zlib failed to initialize compressor");
+ }
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ /* libpng is not interested in zstream.data_type */
+ /* Set it to a predefined value, to avoid its evaluation inside zlib */
+ png_ptr->zstream.data_type = Z_BINARY;
+
+ png_ptr->mode = PNG_HAVE_IHDR;
+}
+
+/* Write the palette. We are careful not to trust png_color to be in the
+ * correct order for PNG, so people can redefine it to any convenient
+ * structure.
+ */
+void /* PRIVATE */
+png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
+{
+ PNG_PLTE;
+ png_uint_32 i;
+ png_colorp pal_ptr;
+ png_byte buf[3];
+
+ png_debug(1, "in png_write_PLTE");
+
+ if ((
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
+#endif
+ num_pal == 0) || num_pal > 256)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_error(png_ptr, "Invalid number of colors in palette");
+ }
+ else
+ {
+ png_warning(png_ptr, "Invalid number of colors in palette");
+ return;
+ }
+ }
+
+ if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
+ {
+ png_warning(png_ptr,
+ "Ignoring request to write a PLTE chunk in grayscale PNG");
+ return;
+ }
+
+ png_ptr->num_palette = (png_uint_16)num_pal;
+ png_debug1(3, "num_palette = %d", png_ptr->num_palette);
+
+ png_write_chunk_start(png_ptr, (png_bytep)png_PLTE,
+ (png_uint_32)(num_pal * 3));
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
+ {
+ buf[0] = pal_ptr->red;
+ buf[1] = pal_ptr->green;
+ buf[2] = pal_ptr->blue;
+ png_write_chunk_data(png_ptr, buf, (png_size_t)3);
+ }
+#else
+ /* This is a little slower but some buggy compilers need to do this
+ * instead
+ */
+ pal_ptr=palette;
+ for (i = 0; i < num_pal; i++)
+ {
+ buf[0] = pal_ptr[i].red;
+ buf[1] = pal_ptr[i].green;
+ buf[2] = pal_ptr[i].blue;
+ png_write_chunk_data(png_ptr, buf, (png_size_t)3);
+ }
+#endif
+ png_write_chunk_end(png_ptr);
+ png_ptr->mode |= PNG_HAVE_PLTE;
+}
+
+/* Write an IDAT chunk */
+void /* PRIVATE */
+png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+ PNG_IDAT;
+
+ png_debug(1, "in png_write_IDAT");
+
+ /* Optimize the CMF field in the zlib stream. */
+ /* This hack of the zlib stream is compliant to the stream specification. */
+ if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
+ png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+ {
+ unsigned int z_cmf = data[0]; /* zlib compression method and flags */
+ if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
+ {
+ /* Avoid memory underflows and multiplication overflows.
+ *
+ * The conditions below are practically always satisfied;
+ * however, they still must be checked.
+ */
+ if (length >= 2 &&
+ png_ptr->height < 16384 && png_ptr->width < 16384)
+ {
+ png_uint_32 uncompressed_idat_size = png_ptr->height *
+ ((png_ptr->width *
+ png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
+ unsigned int z_cinfo = z_cmf >> 4;
+ unsigned int half_z_window_size = 1 << (z_cinfo + 7);
+ while (uncompressed_idat_size <= half_z_window_size &&
+ half_z_window_size >= 256)
+ {
+ z_cinfo--;
+ half_z_window_size >>= 1;
+ }
+ z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
+ if (data[0] != (png_byte)z_cmf)
+ {
+ data[0] = (png_byte)z_cmf;
+ data[1] &= 0xe0;
+ data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f);
+ }
+ }
+ }
+ else
+ png_error(png_ptr,
+ "Invalid zlib compression method or flags in IDAT");
+ }
+
+ png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
+ png_ptr->mode |= PNG_HAVE_IDAT;
+}
+
+/* Write an IEND chunk */
+void /* PRIVATE */
+png_write_IEND(png_structp png_ptr)
+{
+ PNG_IEND;
+
+ png_debug(1, "in png_write_IEND");
+
+ png_write_chunk(png_ptr, (png_bytep)png_IEND, NULL,
+ (png_size_t)0);
+ png_ptr->mode |= PNG_HAVE_IEND;
+}
+
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+/* Write a gAMA chunk */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void /* PRIVATE */
+png_write_gAMA(png_structp png_ptr, double file_gamma)
+{
+ PNG_gAMA;
+ png_uint_32 igamma;
+ png_byte buf[4];
+
+ png_debug(1, "in png_write_gAMA");
+
+ /* file_gamma is saved in 1/100,000ths */
+ igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
+ png_save_uint_32(buf, igamma);
+ png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
+}
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void /* PRIVATE */
+png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
+{
+ PNG_gAMA;
+ png_byte buf[4];
+
+ png_debug(1, "in png_write_gAMA");
+
+ /* file_gamma is saved in 1/100,000ths */
+ png_save_uint_32(buf, (png_uint_32)file_gamma);
+ png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
+}
+#endif
+#endif
+
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+/* Write a sRGB chunk */
+void /* PRIVATE */
+png_write_sRGB(png_structp png_ptr, int srgb_intent)
+{
+ PNG_sRGB;
+ png_byte buf[1];
+
+ png_debug(1, "in png_write_sRGB");
+
+ if (srgb_intent >= PNG_sRGB_INTENT_LAST)
+ png_warning(png_ptr,
+ "Invalid sRGB rendering intent specified");
+ buf[0]=(png_byte)srgb_intent;
+ png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
+}
+#endif
+
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+/* Write an iCCP chunk */
+void /* PRIVATE */
+png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
+ png_charp profile, int profile_len)
+{
+ PNG_iCCP;
+ png_size_t name_len;
+ png_charp new_name;
+ compression_state comp;
+ int embedded_profile_len = 0;
+
+ png_debug(1, "in png_write_iCCP");
+
+ comp.num_output_ptr = 0;
+ comp.max_output_ptr = 0;
+ comp.output_ptr = NULL;
+ comp.input = NULL;
+ comp.input_len = 0;
+
+ if ((name_len = png_check_keyword(png_ptr, name,
+ &new_name)) == 0)
+ return;
+
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+ png_warning(png_ptr, "Unknown compression type in iCCP chunk");
+
+ if (profile == NULL)
+ profile_len = 0;
+
+ if (profile_len > 3)
+ embedded_profile_len =
+ ((*( (png_bytep)profile ))<<24) |
+ ((*( (png_bytep)profile + 1))<<16) |
+ ((*( (png_bytep)profile + 2))<< 8) |
+ ((*( (png_bytep)profile + 3)) );
+
+ if (embedded_profile_len < 0)
+ {
+ png_warning(png_ptr,
+ "Embedded profile length in iCCP chunk is negative");
+ png_free(png_ptr, new_name);
+ return;
+ }
+
+ if (profile_len < embedded_profile_len)
+ {
+ png_warning(png_ptr,
+ "Embedded profile length too large in iCCP chunk");
+ png_free(png_ptr, new_name);
+ return;
+ }
+
+ if (profile_len > embedded_profile_len)
+ {
+ png_warning(png_ptr,
+ "Truncating profile to actual length in iCCP chunk");
+ profile_len = embedded_profile_len;
+ }
+
+ if (profile_len)
+ profile_len = png_text_compress(png_ptr, profile,
+ (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);
+
+ /* Make sure we include the NULL after the name and the compression type */
+ png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
+ (png_uint_32)(name_len + profile_len + 2));
+ new_name[name_len + 1] = 0x00;
+ png_write_chunk_data(png_ptr, (png_bytep)new_name,
+ (png_size_t)(name_len + 2));
+
+ if (profile_len)
+ png_write_compressed_data_out(png_ptr, &comp);
+
+ png_write_chunk_end(png_ptr);
+ png_free(png_ptr, new_name);
+}
+#endif
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+/* Write a sPLT chunk */
+void /* PRIVATE */
+png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
+{
+ PNG_sPLT;
+ png_size_t name_len;
+ png_charp new_name;
+ png_byte entrybuf[10];
+ png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
+ png_size_t palette_size = entry_size * spalette->nentries;
+ png_sPLT_entryp ep;
+#ifndef PNG_POINTER_INDEXING_SUPPORTED
+ int i;
+#endif
+
+ png_debug(1, "in png_write_sPLT");
+
+ if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0)
+ return;
+
+ /* Make sure we include the NULL after the name */
+ png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
+ (png_uint_32)(name_len + 2 + palette_size));
+ png_write_chunk_data(png_ptr, (png_bytep)new_name,
+ (png_size_t)(name_len + 1));
+ png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, (png_size_t)1);
+
+ /* Loop through each palette entry, writing appropriately */
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
+ {
+ if (spalette->depth == 8)
+ {
+ entrybuf[0] = (png_byte)ep->red;
+ entrybuf[1] = (png_byte)ep->green;
+ entrybuf[2] = (png_byte)ep->blue;
+ entrybuf[3] = (png_byte)ep->alpha;
+ png_save_uint_16(entrybuf + 4, ep->frequency);
+ }
+ else
+ {
+ png_save_uint_16(entrybuf + 0, ep->red);
+ png_save_uint_16(entrybuf + 2, ep->green);
+ png_save_uint_16(entrybuf + 4, ep->blue);
+ png_save_uint_16(entrybuf + 6, ep->alpha);
+ png_save_uint_16(entrybuf + 8, ep->frequency);
+ }
+ png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
+ }
+#else
+ ep=spalette->entries;
+ for (i=0; i>spalette->nentries; i++)
+ {
+ if (spalette->depth == 8)
+ {
+ entrybuf[0] = (png_byte)ep[i].red;
+ entrybuf[1] = (png_byte)ep[i].green;
+ entrybuf[2] = (png_byte)ep[i].blue;
+ entrybuf[3] = (png_byte)ep[i].alpha;
+ png_save_uint_16(entrybuf + 4, ep[i].frequency);
+ }
+ else
+ {
+ png_save_uint_16(entrybuf + 0, ep[i].red);
+ png_save_uint_16(entrybuf + 2, ep[i].green);
+ png_save_uint_16(entrybuf + 4, ep[i].blue);
+ png_save_uint_16(entrybuf + 6, ep[i].alpha);
+ png_save_uint_16(entrybuf + 8, ep[i].frequency);
+ }
+ png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
+ }
+#endif
+
+ png_write_chunk_end(png_ptr);
+ png_free(png_ptr, new_name);
+}
+#endif
+
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+/* Write the sBIT chunk */
+void /* PRIVATE */
+png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
+{
+ PNG_sBIT;
+ png_byte buf[4];
+ png_size_t size;
+
+ png_debug(1, "in png_write_sBIT");
+
+ /* Make sure we don't depend upon the order of PNG_COLOR_8 */
+ if (color_type & PNG_COLOR_MASK_COLOR)
+ {
+ png_byte maxbits;
+
+ maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
+ png_ptr->usr_bit_depth);
+ if (sbit->red == 0 || sbit->red > maxbits ||
+ sbit->green == 0 || sbit->green > maxbits ||
+ sbit->blue == 0 || sbit->blue > maxbits)
+ {
+ png_warning(png_ptr, "Invalid sBIT depth specified");
+ return;
+ }
+ buf[0] = sbit->red;
+ buf[1] = sbit->green;
+ buf[2] = sbit->blue;
+ size = 3;
+ }
+ else
+ {
+ if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
+ {
+ png_warning(png_ptr, "Invalid sBIT depth specified");
+ return;
+ }
+ buf[0] = sbit->gray;
+ size = 1;
+ }
+
+ if (color_type & PNG_COLOR_MASK_ALPHA)
+ {
+ if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
+ {
+ png_warning(png_ptr, "Invalid sBIT depth specified");
+ return;
+ }
+ buf[size++] = sbit->alpha;
+ }
+
+ png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
+}
+#endif
+
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+/* Write the cHRM chunk */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void /* PRIVATE */
+png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
+ double red_x, double red_y, double green_x, double green_y,
+ double blue_x, double blue_y)
+{
+ PNG_cHRM;
+ png_byte buf[32];
+
+ png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y,
+ int_green_x, int_green_y, int_blue_x, int_blue_y;
+
+ png_debug(1, "in png_write_cHRM");
+
+ int_white_x = (png_uint_32)(white_x * 100000.0 + 0.5);
+ int_white_y = (png_uint_32)(white_y * 100000.0 + 0.5);
+ int_red_x = (png_uint_32)(red_x * 100000.0 + 0.5);
+ int_red_y = (png_uint_32)(red_y * 100000.0 + 0.5);
+ int_green_x = (png_uint_32)(green_x * 100000.0 + 0.5);
+ int_green_y = (png_uint_32)(green_y * 100000.0 + 0.5);
+ int_blue_x = (png_uint_32)(blue_x * 100000.0 + 0.5);
+ int_blue_y = (png_uint_32)(blue_y * 100000.0 + 0.5);
+
+#ifdef PNG_CHECK_cHRM_SUPPORTED
+ if (png_check_cHRM_fixed(png_ptr, int_white_x, int_white_y,
+ int_red_x, int_red_y, int_green_x, int_green_y, int_blue_x, int_blue_y))
+#endif
+ {
+ /* Each value is saved in 1/100,000ths */
+
+ png_save_uint_32(buf, int_white_x);
+ png_save_uint_32(buf + 4, int_white_y);
+
+ png_save_uint_32(buf + 8, int_red_x);
+ png_save_uint_32(buf + 12, int_red_y);
+
+ png_save_uint_32(buf + 16, int_green_x);
+ png_save_uint_32(buf + 20, int_green_y);
+
+ png_save_uint_32(buf + 24, int_blue_x);
+ png_save_uint_32(buf + 28, int_blue_y);
+
+ png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
+ }
+}
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void /* PRIVATE */
+png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
+ png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
+ png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
+ png_fixed_point blue_y)
+{
+ PNG_cHRM;
+ png_byte buf[32];
+
+ png_debug(1, "in png_write_cHRM");
+
+ /* Each value is saved in 1/100,000ths */
+#ifdef PNG_CHECK_cHRM_SUPPORTED
+ if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y,
+ green_x, green_y, blue_x, blue_y))
+#endif
+ {
+ png_save_uint_32(buf, (png_uint_32)white_x);
+ png_save_uint_32(buf + 4, (png_uint_32)white_y);
+
+ png_save_uint_32(buf + 8, (png_uint_32)red_x);
+ png_save_uint_32(buf + 12, (png_uint_32)red_y);
+
+ png_save_uint_32(buf + 16, (png_uint_32)green_x);
+ png_save_uint_32(buf + 20, (png_uint_32)green_y);
+
+ png_save_uint_32(buf + 24, (png_uint_32)blue_x);
+ png_save_uint_32(buf + 28, (png_uint_32)blue_y);
+
+ png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
+ }
+}
+#endif
+#endif
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+/* Write the tRNS chunk */
+void /* PRIVATE */
+png_write_tRNS(png_structp png_ptr, png_bytep trans_alpha, png_color_16p tran,
+ int num_trans, int color_type)
+{
+ PNG_tRNS;
+ png_byte buf[6];
+
+ png_debug(1, "in png_write_tRNS");
+
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
+ {
+ png_warning(png_ptr, "Invalid number of transparent colors specified");
+ return;
+ }
+ /* Write the chunk out as it is */
+ png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans_alpha,
+ (png_size_t)num_trans);
+ }
+ else if (color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ /* One 16 bit value */
+ if (tran->gray >= (1 << png_ptr->bit_depth))
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
+ return;
+ }
+ png_save_uint_16(buf, tran->gray);
+ png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
+ }
+ else if (color_type == PNG_COLOR_TYPE_RGB)
+ {
+ /* Three 16 bit values */
+ png_save_uint_16(buf, tran->red);
+ png_save_uint_16(buf + 2, tran->green);
+ png_save_uint_16(buf + 4, tran->blue);
+ if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
+ return;
+ }
+ png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
+ }
+ else
+ {
+ png_warning(png_ptr, "Can't write tRNS with an alpha channel");
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+/* Write the background chunk */
+void /* PRIVATE */
+png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
+{
+ PNG_bKGD;
+ png_byte buf[6];
+
+ png_debug(1, "in png_write_bKGD");
+
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ (png_ptr->num_palette ||
+ (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
+#endif
+ back->index >= png_ptr->num_palette)
+ {
+ png_warning(png_ptr, "Invalid background palette index");
+ return;
+ }
+ buf[0] = back->index;
+ png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
+ }
+ else if (color_type & PNG_COLOR_MASK_COLOR)
+ {
+ png_save_uint_16(buf, back->red);
+ png_save_uint_16(buf + 2, back->green);
+ png_save_uint_16(buf + 4, back->blue);
+ if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
+ return;
+ }
+ png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
+ }
+ else
+ {
+ if (back->gray >= (1 << png_ptr->bit_depth))
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
+ return;
+ }
+ png_save_uint_16(buf, back->gray);
+ png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+/* Write the histogram */
+void /* PRIVATE */
+png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
+{
+ PNG_hIST;
+ int i;
+ png_byte buf[3];
+
+ png_debug(1, "in png_write_hIST");
+
+ if (num_hist > (int)png_ptr->num_palette)
+ {
+ png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
+ png_ptr->num_palette);
+ png_warning(png_ptr, "Invalid number of histogram entries specified");
+ return;
+ }
+
+ png_write_chunk_start(png_ptr, (png_bytep)png_hIST,
+ (png_uint_32)(num_hist * 2));
+ for (i = 0; i < num_hist; i++)
+ {
+ png_save_uint_16(buf, hist[i]);
+ png_write_chunk_data(png_ptr, buf, (png_size_t)2);
+ }
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
+ defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
+ * and if invalid, correct the keyword rather than discarding the entire
+ * chunk. The PNG 1.0 specification requires keywords 1-79 characters in
+ * length, forbids leading or trailing whitespace, multiple internal spaces,
+ * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
+ *
+ * The new_key is allocated to hold the corrected keyword and must be freed
+ * by the calling routine. This avoids problems with trying to write to
+ * static keywords without having to have duplicate copies of the strings.
+ */
+png_size_t /* PRIVATE */
+png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
+{
+ png_size_t key_len;
+ png_charp kp, dp;
+ int kflag;
+ int kwarn=0;
+
+ png_debug(1, "in png_check_keyword");
+
+ *new_key = NULL;
+
+ if (key == NULL || (key_len = png_strlen(key)) == 0)
+ {
+ png_warning(png_ptr, "zero length keyword");
+ return ((png_size_t)0);
+ }
+
+ png_debug1(2, "Keyword to be checked is '%s'", key);
+
+ *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
+ if (*new_key == NULL)
+ {
+ png_warning(png_ptr, "Out of memory while procesing keyword");
+ return ((png_size_t)0);
+ }
+
+ /* Replace non-printing characters with a blank and print a warning */
+ for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)
+ {
+ if ((png_byte)*kp < 0x20 ||
+ ((png_byte)*kp > 0x7E && (png_byte)*kp < 0xA1))
+ {
+#ifdef PNG_STDIO_SUPPORTED
+ char msg[40];
+
+ png_snprintf(msg, 40,
+ "invalid keyword character 0x%02X", (png_byte)*kp);
+ png_warning(png_ptr, msg);
+#else
+ png_warning(png_ptr, "invalid character in keyword");
+#endif
+ *dp = ' ';
+ }
+ else
+ {
+ *dp = *kp;
+ }
+ }
+ *dp = '\0';
+
+ /* Remove any trailing white space. */
+ kp = *new_key + key_len - 1;
+ if (*kp == ' ')
+ {
+ png_warning(png_ptr, "trailing spaces removed from keyword");
+
+ while (*kp == ' ')
+ {
+ *(kp--) = '\0';
+ key_len--;
+ }
+ }
+
+ /* Remove any leading white space. */
+ kp = *new_key;
+ if (*kp == ' ')
+ {
+ png_warning(png_ptr, "leading spaces removed from keyword");
+
+ while (*kp == ' ')
+ {
+ kp++;
+ key_len--;
+ }
+ }
+
+ png_debug1(2, "Checking for multiple internal spaces in '%s'", kp);
+
+ /* Remove multiple internal spaces. */
+ for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
+ {
+ if (*kp == ' ' && kflag == 0)
+ {
+ *(dp++) = *kp;
+ kflag = 1;
+ }
+ else if (*kp == ' ')
+ {
+ key_len--;
+ kwarn=1;
+ }
+ else
+ {
+ *(dp++) = *kp;
+ kflag = 0;
+ }
+ }
+ *dp = '\0';
+ if (kwarn)
+ png_warning(png_ptr, "extra interior spaces removed from keyword");
+
+ if (key_len == 0)
+ {
+ png_free(png_ptr, *new_key);
+ png_warning(png_ptr, "Zero length keyword");
+ }
+
+ if (key_len > 79)
+ {
+ png_warning(png_ptr, "keyword length must be 1 - 79 characters");
+ (*new_key)[79] = '\0';
+ key_len = 79;
+ }
+
+ return (key_len);
+}
+#endif
+
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+/* Write a tEXt chunk */
+void /* PRIVATE */
+png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
+ png_size_t text_len)
+{
+ PNG_tEXt;
+ png_size_t key_len;
+ png_charp new_key;
+
+ png_debug(1, "in png_write_tEXt");
+
+ if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
+ return;
+
+ if (text == NULL || *text == '\0')
+ text_len = 0;
+ else
+ text_len = png_strlen(text);
+
+ /* Make sure we include the 0 after the key */
+ png_write_chunk_start(png_ptr, (png_bytep)png_tEXt,
+ (png_uint_32)(key_len + text_len + 1));
+ /*
+ * We leave it to the application to meet PNG-1.0 requirements on the
+ * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
+ * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
+ * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+ */
+ png_write_chunk_data(png_ptr, (png_bytep)new_key,
+ (png_size_t)(key_len + 1));
+ if (text_len)
+ png_write_chunk_data(png_ptr, (png_bytep)text, (png_size_t)text_len);
+
+ png_write_chunk_end(png_ptr);
+ png_free(png_ptr, new_key);
+}
+#endif
+
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+/* Write a compressed text chunk */
+void /* PRIVATE */
+png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
+ png_size_t text_len, int compression)
+{
+ PNG_zTXt;
+ png_size_t key_len;
+ char buf[1];
+ png_charp new_key;
+ compression_state comp;
+
+ png_debug(1, "in png_write_zTXt");
+
+ comp.num_output_ptr = 0;
+ comp.max_output_ptr = 0;
+ comp.output_ptr = NULL;
+ comp.input = NULL;
+ comp.input_len = 0;
+
+ if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
+ {
+ png_free(png_ptr, new_key);
+ return;
+ }
+
+ if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
+ {
+ png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
+ png_free(png_ptr, new_key);
+ return;
+ }
+
+ text_len = png_strlen(text);
+
+ /* Compute the compressed data; do it now for the length */
+ text_len = png_text_compress(png_ptr, text, text_len, compression,
+ &comp);
+
+ /* Write start of chunk */
+ png_write_chunk_start(png_ptr, (png_bytep)png_zTXt,
+ (png_uint_32)(key_len+text_len + 2));
+ /* Write key */
+ png_write_chunk_data(png_ptr, (png_bytep)new_key,
+ (png_size_t)(key_len + 1));
+ png_free(png_ptr, new_key);
+
+ buf[0] = (png_byte)compression;
+ /* Write compression */
+ png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);
+ /* Write the compressed data */
+ png_write_compressed_data_out(png_ptr, &comp);
+
+ /* Close the chunk */
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+/* Write an iTXt chunk */
+void /* PRIVATE */
+png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
+ png_charp lang, png_charp lang_key, png_charp text)
+{
+ PNG_iTXt;
+ png_size_t lang_len, key_len, lang_key_len, text_len;
+ png_charp new_lang;
+ png_charp new_key = NULL;
+ png_byte cbuf[2];
+ compression_state comp;
+
+ png_debug(1, "in png_write_iTXt");
+
+ comp.num_output_ptr = 0;
+ comp.max_output_ptr = 0;
+ comp.output_ptr = NULL;
+ comp.input = NULL;
+
+ if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
+ return;
+
+ if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)
+ {
+ png_warning(png_ptr, "Empty language field in iTXt chunk");
+ new_lang = NULL;
+ lang_len = 0;
+ }
+
+ if (lang_key == NULL)
+ lang_key_len = 0;
+ else
+ lang_key_len = png_strlen(lang_key);
+
+ if (text == NULL)
+ text_len = 0;
+ else
+ text_len = png_strlen(text);
+
+ /* Compute the compressed data; do it now for the length */
+ text_len = png_text_compress(png_ptr, text, text_len, compression-2,
+ &comp);
+
+
+ /* Make sure we include the compression flag, the compression byte,
+ * and the NULs after the key, lang, and lang_key parts */
+
+ png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
+ (png_uint_32)(
+ 5 /* comp byte, comp flag, terminators for key, lang and lang_key */
+ + key_len
+ + lang_len
+ + lang_key_len
+ + text_len));
+
+ /* We leave it to the application to meet PNG-1.0 requirements on the
+ * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
+ * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
+ * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+ */
+ png_write_chunk_data(png_ptr, (png_bytep)new_key,
+ (png_size_t)(key_len + 1));
+
+ /* Set the compression flag */
+ if (compression == PNG_ITXT_COMPRESSION_NONE || \
+ compression == PNG_TEXT_COMPRESSION_NONE)
+ cbuf[0] = 0;
+ else /* compression == PNG_ITXT_COMPRESSION_zTXt */
+ cbuf[0] = 1;
+ /* Set the compression method */
+ cbuf[1] = 0;
+ png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);
+
+ cbuf[0] = 0;
+ png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf),
+ (png_size_t)(lang_len + 1));
+ png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf),
+ (png_size_t)(lang_key_len + 1));
+ png_write_compressed_data_out(png_ptr, &comp);
+
+ png_write_chunk_end(png_ptr);
+ png_free(png_ptr, new_key);
+ png_free(png_ptr, new_lang);
+}
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+/* Write the oFFs chunk */
+void /* PRIVATE */
+png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
+ int unit_type)
+{
+ PNG_oFFs;
+ png_byte buf[9];
+
+ png_debug(1, "in png_write_oFFs");
+
+ if (unit_type >= PNG_OFFSET_LAST)
+ png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
+
+ png_save_int_32(buf, x_offset);
+ png_save_int_32(buf + 4, y_offset);
+ buf[8] = (png_byte)unit_type;
+
+ png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
+}
+#endif
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+/* Write the pCAL chunk (described in the PNG extensions document) */
+void /* PRIVATE */
+png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
+ png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
+{
+ PNG_pCAL;
+ png_size_t purpose_len, units_len, total_len;
+ png_uint_32p params_len;
+ png_byte buf[10];
+ png_charp new_purpose;
+ int i;
+
+ png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
+
+ if (type >= PNG_EQUATION_LAST)
+ png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
+
+ purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
+ png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
+ units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
+ png_debug1(3, "pCAL units length = %d", (int)units_len);
+ total_len = purpose_len + units_len + 10;
+
+ params_len = (png_uint_32p)png_malloc(png_ptr,
+ (png_alloc_size_t)(nparams * png_sizeof(png_uint_32)));
+
+ /* Find the length of each parameter, making sure we don't count the
+ null terminator for the last parameter. */
+ for (i = 0; i < nparams; i++)
+ {
+ params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
+ png_debug2(3, "pCAL parameter %d length = %lu", i,
+ (unsigned long) params_len[i]);
+ total_len += (png_size_t)params_len[i];
+ }
+
+ png_debug1(3, "pCAL total length = %d", (int)total_len);
+ png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);
+ png_write_chunk_data(png_ptr, (png_bytep)new_purpose,
+ (png_size_t)purpose_len);
+ png_save_int_32(buf, X0);
+ png_save_int_32(buf + 4, X1);
+ buf[8] = (png_byte)type;
+ buf[9] = (png_byte)nparams;
+ png_write_chunk_data(png_ptr, buf, (png_size_t)10);
+ png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len);
+
+ png_free(png_ptr, new_purpose);
+
+ for (i = 0; i < nparams; i++)
+ {
+ png_write_chunk_data(png_ptr, (png_bytep)params[i],
+ (png_size_t)params_len[i]);
+ }
+
+ png_free(png_ptr, params_len);
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+/* Write the sCAL chunk */
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
+void /* PRIVATE */
+png_write_sCAL(png_structp png_ptr, int unit, double width, double height)
+{
+ PNG_sCAL;
+ char buf[64];
+ png_size_t total_len;
+
+ png_debug(1, "in png_write_sCAL");
+
+ buf[0] = (char)unit;
+ png_snprintf(buf + 1, 63, "%12.12e", width);
+ total_len = 1 + png_strlen(buf + 1) + 1;
+ png_snprintf(buf + total_len, 64-total_len, "%12.12e", height);
+ total_len += png_strlen(buf + total_len);
+
+ png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
+ png_write_chunk(png_ptr, (png_bytep)png_sCAL, (png_bytep)buf, total_len);
+}
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void /* PRIVATE */
+png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
+ png_charp height)
+{
+ PNG_sCAL;
+ png_byte buf[64];
+ png_size_t wlen, hlen, total_len;
+
+ png_debug(1, "in png_write_sCAL_s");
+
+ wlen = png_strlen(width);
+ hlen = png_strlen(height);
+ total_len = wlen + hlen + 2;
+ if (total_len > 64)
+ {
+ png_warning(png_ptr, "Can't write sCAL (buffer too small)");
+ return;
+ }
+
+ buf[0] = (png_byte)unit;
+ png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
+ png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
+
+ png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
+ png_write_chunk(png_ptr, (png_bytep)png_sCAL, buf, total_len);
+}
+#endif
+#endif
+#endif
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+/* Write the pHYs chunk */
+void /* PRIVATE */
+png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
+ png_uint_32 y_pixels_per_unit,
+ int unit_type)
+{
+ PNG_pHYs;
+ png_byte buf[9];
+
+ png_debug(1, "in png_write_pHYs");
+
+ if (unit_type >= PNG_RESOLUTION_LAST)
+ png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
+
+ png_save_uint_32(buf, x_pixels_per_unit);
+ png_save_uint_32(buf + 4, y_pixels_per_unit);
+ buf[8] = (png_byte)unit_type;
+
+ png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
+}
+#endif
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+/* Write the tIME chunk. Use either png_convert_from_struct_tm()
+ * or png_convert_from_time_t(), or fill in the structure yourself.
+ */
+void /* PRIVATE */
+png_write_tIME(png_structp png_ptr, png_timep mod_time)
+{
+ PNG_tIME;
+ png_byte buf[7];
+
+ png_debug(1, "in png_write_tIME");
+
+ if (mod_time->month > 12 || mod_time->month < 1 ||
+ mod_time->day > 31 || mod_time->day < 1 ||
+ mod_time->hour > 23 || mod_time->second > 60)
+ {
+ png_warning(png_ptr, "Invalid time specified for tIME chunk");
+ return;
+ }
+
+ png_save_uint_16(buf, mod_time->year);
+ buf[2] = mod_time->month;
+ buf[3] = mod_time->day;
+ buf[4] = mod_time->hour;
+ buf[5] = mod_time->minute;
+ buf[6] = mod_time->second;
+
+ png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
+}
+#endif
+
+/* Initializes the row writing capability of libpng */
+void /* PRIVATE */
+png_write_start_row(png_structp png_ptr)
+{
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
+ png_size_t buf_size;
+
+ png_debug(1, "in png_write_start_row");
+
+ buf_size = (png_size_t)(PNG_ROWBYTES(
+ png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1);
+
+ /* Set up row buffer */
+ png_ptr->row_buf = (png_bytep)png_malloc(png_ptr,
+ (png_alloc_size_t)buf_size);
+ png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ /* Set up filtering buffer, if using this filter */
+ if (png_ptr->do_filter & PNG_FILTER_SUB)
+ {
+ png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
+ (png_alloc_size_t)(png_ptr->rowbytes + 1));
+ png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
+ }
+
+ /* We only need to keep the previous row if we are using one of these. */
+ if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
+ {
+ /* Set up previous row buffer */
+ png_ptr->prev_row = (png_bytep)png_calloc(png_ptr,
+ (png_alloc_size_t)buf_size);
+
+ if (png_ptr->do_filter & PNG_FILTER_UP)
+ {
+ png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
+ (png_size_t)(png_ptr->rowbytes + 1));
+ png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
+ }
+
+ if (png_ptr->do_filter & PNG_FILTER_AVG)
+ {
+ png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
+ (png_alloc_size_t)(png_ptr->rowbytes + 1));
+ png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
+ }
+
+ if (png_ptr->do_filter & PNG_FILTER_PAETH)
+ {
+ png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
+ (png_size_t)(png_ptr->rowbytes + 1));
+ png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
+ }
+ }
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* If interlaced, we need to set up width and height of pass */
+ if (png_ptr->interlaced)
+ {
+ if (!(png_ptr->transformations & PNG_INTERLACE))
+ {
+ png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+ png_pass_ystart[0]) / png_pass_yinc[0];
+ png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
+ png_pass_start[0]) / png_pass_inc[0];
+ }
+ else
+ {
+ png_ptr->num_rows = png_ptr->height;
+ png_ptr->usr_width = png_ptr->width;
+ }
+ }
+ else
+#endif
+ {
+ png_ptr->num_rows = png_ptr->height;
+ png_ptr->usr_width = png_ptr->width;
+ }
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+}
+
+/* Internal use only. Called when finished processing a row of data. */
+void /* PRIVATE */
+png_write_finish_row(png_structp png_ptr)
+{
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
+ int ret;
+
+ png_debug(1, "in png_write_finish_row");
+
+ /* Next row */
+ png_ptr->row_number++;
+
+ /* See if we are done */
+ if (png_ptr->row_number < png_ptr->num_rows)
+ return;
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* If interlaced, go to next pass */
+ if (png_ptr->interlaced)
+ {
+ png_ptr->row_number = 0;
+ if (png_ptr->transformations & PNG_INTERLACE)
+ {
+ png_ptr->pass++;
+ }
+ else
+ {
+ /* Loop until we find a non-zero width or height pass */
+ do
+ {
+ png_ptr->pass++;
+ if (png_ptr->pass >= 7)
+ break;
+ png_ptr->usr_width = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+ png_ptr->num_rows = (png_ptr->height +
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
+ if (png_ptr->transformations & PNG_INTERLACE)
+ break;
+ } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
+
+ }
+
+ /* Reset the row above the image for the next pass */
+ if (png_ptr->pass < 7)
+ {
+ if (png_ptr->prev_row != NULL)
+ png_memset(png_ptr->prev_row, 0,
+ (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
+ png_ptr->usr_bit_depth, png_ptr->width)) + 1);
+ return;
+ }
+ }
+#endif
+
+ /* If we get here, we've just written the last row, so we need
+ to flush the compressor */
+ do
+ {
+ /* Tell the compressor we are done */
+ ret = deflate(&png_ptr->zstream, Z_FINISH);
+ /* Check for an error */
+ if (ret == Z_OK)
+ {
+ /* Check to see if we need more room */
+ if (!(png_ptr->zstream.avail_out))
+ {
+ png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ }
+ }
+ else if (ret != Z_STREAM_END)
+ {
+ if (png_ptr->zstream.msg != NULL)
+ png_error(png_ptr, png_ptr->zstream.msg);
+ else
+ png_error(png_ptr, "zlib error");
+ }
+ } while (ret != Z_STREAM_END);
+
+ /* Write any extra space */
+ if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
+ {
+ png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
+ png_ptr->zstream.avail_out);
+ }
+
+ deflateReset(&png_ptr->zstream);
+ png_ptr->zstream.data_type = Z_BINARY;
+}
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+/* Pick out the correct pixels for the interlace pass.
+ * The basic idea here is to go through the row with a source
+ * pointer and a destination pointer (sp and dp), and copy the
+ * correct pixels for the pass. As the row gets compacted,
+ * sp will always be >= dp, so we should never overwrite anything.
+ * See the default: case for the easiest code to understand.
+ */
+void /* PRIVATE */
+png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
+{
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ png_debug(1, "in png_do_write_interlace");
+
+ /* We don't have to do anything on the last pass (6) */
+ if (pass < 6)
+ {
+ /* Each pixel depth is handled separately */
+ switch (row_info->pixel_depth)
+ {
+ case 1:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ int shift;
+ int d;
+ int value;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ dp = row;
+ d = 0;
+ shift = 7;
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ sp = row + (png_size_t)(i >> 3);
+ value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
+ d |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 7;
+ *dp++ = (png_byte)d;
+ d = 0;
+ }
+ else
+ shift--;
+
+ }
+ if (shift != 7)
+ *dp = (png_byte)d;
+ break;
+ }
+ case 2:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ int shift;
+ int d;
+ int value;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ dp = row;
+ shift = 6;
+ d = 0;
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ sp = row + (png_size_t)(i >> 2);
+ value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
+ d |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 6;
+ *dp++ = (png_byte)d;
+ d = 0;
+ }
+ else
+ shift -= 2;
+ }
+ if (shift != 6)
+ *dp = (png_byte)d;
+ break;
+ }
+ case 4:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ int shift;
+ int d;
+ int value;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ dp = row;
+ shift = 4;
+ d = 0;
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ sp = row + (png_size_t)(i >> 1);
+ value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
+ d |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 4;
+ *dp++ = (png_byte)d;
+ d = 0;
+ }
+ else
+ shift -= 4;
+ }
+ if (shift != 4)
+ *dp = (png_byte)d;
+ break;
+ }
+ default:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+ png_size_t pixel_bytes;
+
+ /* Start at the beginning */
+ dp = row;
+ /* Find out how many bytes each pixel takes up */
+ pixel_bytes = (row_info->pixel_depth >> 3);
+ /* Loop through the row, only looking at the pixels that
+ matter */
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ /* Find out where the original pixel is */
+ sp = row + (png_size_t)i * pixel_bytes;
+ /* Move the pixel */
+ if (dp != sp)
+ png_memcpy(dp, sp, pixel_bytes);
+ /* Next pixel */
+ dp += pixel_bytes;
+ }
+ break;
+ }
+ }
+ /* Set new row width */
+ row_info->width = (row_info->width +
+ png_pass_inc[pass] - 1 -
+ png_pass_start[pass]) /
+ png_pass_inc[pass];
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_info->width);
+ }
+}
+#endif
+
+/* This filters the row, chooses which filter to use, if it has not already
+ * been specified by the application, and then writes the row out with the
+ * chosen filter.
+ */
+#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
+#define PNG_HISHIFT 10
+#define PNG_LOMASK ((png_uint_32)0xffffL)
+#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
+void /* PRIVATE */
+png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
+{
+ png_bytep best_row;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ png_bytep prev_row, row_buf;
+ png_uint_32 mins, bpp;
+ png_byte filter_to_do = png_ptr->do_filter;
+ png_uint_32 row_bytes = row_info->rowbytes;
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ int num_p_filters = (int)png_ptr->num_prev_filters;
+#endif
+
+ png_debug(1, "in png_write_find_filter");
+
+#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
+ {
+ /* These will never be selected so we need not test them. */
+ filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
+ }
+#endif
+
+ /* Find out how many bytes offset each pixel is */
+ bpp = (row_info->pixel_depth + 7) >> 3;
+
+ prev_row = png_ptr->prev_row;
+#endif
+ best_row = png_ptr->row_buf;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ row_buf = best_row;
+ mins = PNG_MAXSUM;
+
+ /* The prediction method we use is to find which method provides the
+ * smallest value when summing the absolute values of the distances
+ * from zero, using anything >= 128 as negative numbers. This is known
+ * as the "minimum sum of absolute differences" heuristic. Other
+ * heuristics are the "weighted minimum sum of absolute differences"
+ * (experimental and can in theory improve compression), and the "zlib
+ * predictive" method (not implemented yet), which does test compressions
+ * of lines using different filter methods, and then chooses the
+ * (series of) filter(s) that give minimum compressed data size (VERY
+ * computationally expensive).
+ *
+ * GRR 980525: consider also
+ * (1) minimum sum of absolute differences from running average (i.e.,
+ * keep running sum of non-absolute differences & count of bytes)
+ * [track dispersion, too? restart average if dispersion too large?]
+ * (1b) minimum sum of absolute differences from sliding average, probably
+ * with window size <= deflate window (usually 32K)
+ * (2) minimum sum of squared differences from zero or running average
+ * (i.e., ~ root-mean-square approach)
+ */
+
+
+ /* We don't need to test the 'no filter' case if this is the only filter
+ * that has been chosen, as it doesn't actually do anything to the data.
+ */
+ if ((filter_to_do & PNG_FILTER_NONE) &&
+ filter_to_do != PNG_FILTER_NONE)
+ {
+ png_bytep rp;
+ png_uint_32 sum = 0;
+ png_uint_32 i;
+ int v;
+
+ for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
+ {
+ v = *rp;
+ sum += (v < 128) ? v : 256 - v;
+ }
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ png_uint_32 sumhi, sumlo;
+ int j;
+ sumlo = sum & PNG_LOMASK;
+ sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
+
+ /* Reduce the sum if we match any of the previous rows */
+ for (j = 0; j < num_p_filters; j++)
+ {
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
+ {
+ sumlo = (sumlo * png_ptr->filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ sumhi = (sumhi * png_ptr->filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ }
+ }
+
+ /* Factor in the cost of this filter (this is here for completeness,
+ * but it makes no sense to have a "cost" for the NONE filter, as
+ * it has the minimum possible computational cost - none).
+ */
+ sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
+ PNG_COST_SHIFT;
+ sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
+ PNG_COST_SHIFT;
+
+ if (sumhi > PNG_HIMASK)
+ sum = PNG_MAXSUM;
+ else
+ sum = (sumhi << PNG_HISHIFT) + sumlo;
+ }
+#endif
+ mins = sum;
+ }
+
+ /* Sub filter */
+ if (filter_to_do == PNG_FILTER_SUB)
+ /* It's the only filter so no testing is needed */
+ {
+ png_bytep rp, lp, dp;
+ png_uint_32 i;
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
+ i++, rp++, dp++)
+ {
+ *dp = *rp;
+ }
+ for (lp = row_buf + 1; i < row_bytes;
+ i++, rp++, lp++, dp++)
+ {
+ *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+ }
+ best_row = png_ptr->sub_row;
+ }
+
+ else if (filter_to_do & PNG_FILTER_SUB)
+ {
+ png_bytep rp, dp, lp;
+ png_uint_32 sum = 0, lmins = mins;
+ png_uint_32 i;
+ int v;
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ /* We temporarily increase the "minimum sum" by the factor we
+ * would reduce the sum of this filter, so that we can do the
+ * early exit comparison without scaling the sum each time.
+ */
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ int j;
+ png_uint_32 lmhi, lmlo;
+ lmlo = lmins & PNG_LOMASK;
+ lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+
+ for (j = 0; j < num_p_filters; j++)
+ {
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
+ {
+ lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ }
+ }
+
+ lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
+ PNG_COST_SHIFT;
+ lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
+ PNG_COST_SHIFT;
+
+ if (lmhi > PNG_HIMASK)
+ lmins = PNG_MAXSUM;
+ else
+ lmins = (lmhi << PNG_HISHIFT) + lmlo;
+ }
+#endif
+
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
+ i++, rp++, dp++)
+ {
+ v = *dp = *rp;
+
+ sum += (v < 128) ? v : 256 - v;
+ }
+ for (lp = row_buf + 1; i < row_bytes;
+ i++, rp++, lp++, dp++)
+ {
+ v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+
+ sum += (v < 128) ? v : 256 - v;
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ int j;
+ png_uint_32 sumhi, sumlo;
+ sumlo = sum & PNG_LOMASK;
+ sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
+
+ for (j = 0; j < num_p_filters; j++)
+ {
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
+ {
+ sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ }
+ }
+
+ sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
+ PNG_COST_SHIFT;
+ sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
+ PNG_COST_SHIFT;
+
+ if (sumhi > PNG_HIMASK)
+ sum = PNG_MAXSUM;
+ else
+ sum = (sumhi << PNG_HISHIFT) + sumlo;
+ }
+#endif
+
+ if (sum < mins)
+ {
+ mins = sum;
+ best_row = png_ptr->sub_row;
+ }
+ }
+
+ /* Up filter */
+ if (filter_to_do == PNG_FILTER_UP)
+ {
+ png_bytep rp, dp, pp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
+ pp = prev_row + 1; i < row_bytes;
+ i++, rp++, pp++, dp++)
+ {
+ *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
+ }
+ best_row = png_ptr->up_row;
+ }
+
+ else if (filter_to_do & PNG_FILTER_UP)
+ {
+ png_bytep rp, dp, pp;
+ png_uint_32 sum = 0, lmins = mins;
+ png_uint_32 i;
+ int v;
+
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ int j;
+ png_uint_32 lmhi, lmlo;
+ lmlo = lmins & PNG_LOMASK;
+ lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+
+ for (j = 0; j < num_p_filters; j++)
+ {
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
+ {
+ lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ }
+ }
+
+ lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
+ PNG_COST_SHIFT;
+ lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
+ PNG_COST_SHIFT;
+
+ if (lmhi > PNG_HIMASK)
+ lmins = PNG_MAXSUM;
+ else
+ lmins = (lmhi << PNG_HISHIFT) + lmlo;
+ }
+#endif
+
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
+ pp = prev_row + 1; i < row_bytes; i++)
+ {
+ v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+
+ sum += (v < 128) ? v : 256 - v;
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ int j;
+ png_uint_32 sumhi, sumlo;
+ sumlo = sum & PNG_LOMASK;
+ sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
+
+ for (j = 0; j < num_p_filters; j++)
+ {
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
+ {
+ sumlo = (sumlo * png_ptr->filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ sumhi = (sumhi * png_ptr->filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ }
+ }
+
+ sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
+ PNG_COST_SHIFT;
+ sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
+ PNG_COST_SHIFT;
+
+ if (sumhi > PNG_HIMASK)
+ sum = PNG_MAXSUM;
+ else
+ sum = (sumhi << PNG_HISHIFT) + sumlo;
+ }
+#endif
+
+ if (sum < mins)
+ {
+ mins = sum;
+ best_row = png_ptr->up_row;
+ }
+ }
+
+ /* Avg filter */
+ if (filter_to_do == PNG_FILTER_AVG)
+ {
+ png_bytep rp, dp, pp, lp;
+ png_uint_32 i;
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
+ pp = prev_row + 1; i < bpp; i++)
+ {
+ *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+ }
+ for (lp = row_buf + 1; i < row_bytes; i++)
+ {
+ *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
+ & 0xff);
+ }
+ best_row = png_ptr->avg_row;
+ }
+
+ else if (filter_to_do & PNG_FILTER_AVG)
+ {
+ png_bytep rp, dp, pp, lp;
+ png_uint_32 sum = 0, lmins = mins;
+ png_uint_32 i;
+ int v;
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ int j;
+ png_uint_32 lmhi, lmlo;
+ lmlo = lmins & PNG_LOMASK;
+ lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+
+ for (j = 0; j < num_p_filters; j++)
+ {
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
+ {
+ lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ }
+ }
+
+ lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
+ PNG_COST_SHIFT;
+ lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
+ PNG_COST_SHIFT;
+
+ if (lmhi > PNG_HIMASK)
+ lmins = PNG_MAXSUM;
+ else
+ lmins = (lmhi << PNG_HISHIFT) + lmlo;
+ }
+#endif
+
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
+ pp = prev_row + 1; i < bpp; i++)
+ {
+ v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+
+ sum += (v < 128) ? v : 256 - v;
+ }
+ for (lp = row_buf + 1; i < row_bytes; i++)
+ {
+ v = *dp++ =
+ (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
+
+ sum += (v < 128) ? v : 256 - v;
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ int j;
+ png_uint_32 sumhi, sumlo;
+ sumlo = sum & PNG_LOMASK;
+ sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
+
+ for (j = 0; j < num_p_filters; j++)
+ {
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
+ {
+ sumlo = (sumlo * png_ptr->filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ sumhi = (sumhi * png_ptr->filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ }
+ }
+
+ sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
+ PNG_COST_SHIFT;
+ sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
+ PNG_COST_SHIFT;
+
+ if (sumhi > PNG_HIMASK)
+ sum = PNG_MAXSUM;
+ else
+ sum = (sumhi << PNG_HISHIFT) + sumlo;
+ }
+#endif
+
+ if (sum < mins)
+ {
+ mins = sum;
+ best_row = png_ptr->avg_row;
+ }
+ }
+
+ /* Paeth filter */
+ if (filter_to_do == PNG_FILTER_PAETH)
+ {
+ png_bytep rp, dp, pp, cp, lp;
+ png_uint_32 i;
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
+ pp = prev_row + 1; i < bpp; i++)
+ {
+ *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+ }
+
+ for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ b = *pp++;
+ c = *cp++;
+ a = *lp++;
+
+ p = b - c;
+ pc = a - c;
+
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+ p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+
+ *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+ }
+ best_row = png_ptr->paeth_row;
+ }
+
+ else if (filter_to_do & PNG_FILTER_PAETH)
+ {
+ png_bytep rp, dp, pp, cp, lp;
+ png_uint_32 sum = 0, lmins = mins;
+ png_uint_32 i;
+ int v;
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ int j;
+ png_uint_32 lmhi, lmlo;
+ lmlo = lmins & PNG_LOMASK;
+ lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+
+ for (j = 0; j < num_p_filters; j++)
+ {
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
+ {
+ lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ }
+ }
+
+ lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
+ PNG_COST_SHIFT;
+ lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
+ PNG_COST_SHIFT;
+
+ if (lmhi > PNG_HIMASK)
+ lmins = PNG_MAXSUM;
+ else
+ lmins = (lmhi << PNG_HISHIFT) + lmlo;
+ }
+#endif
+
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
+ pp = prev_row + 1; i < bpp; i++)
+ {
+ v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+
+ sum += (v < 128) ? v : 256 - v;
+ }
+
+ for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ b = *pp++;
+ c = *cp++;
+ a = *lp++;
+
+#ifndef PNG_SLOW_PAETH
+ p = b - c;
+ pc = a - c;
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+ p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+#else /* PNG_SLOW_PAETH */
+ p = a + b - c;
+ pa = abs(p - a);
+ pb = abs(p - b);
+ pc = abs(p - c);
+ if (pa <= pb && pa <= pc)
+ p = a;
+ else if (pb <= pc)
+ p = b;
+ else
+ p = c;
+#endif /* PNG_SLOW_PAETH */
+
+ v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+
+ sum += (v < 128) ? v : 256 - v;
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ int j;
+ png_uint_32 sumhi, sumlo;
+ sumlo = sum & PNG_LOMASK;
+ sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
+
+ for (j = 0; j < num_p_filters; j++)
+ {
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
+ {
+ sumlo = (sumlo * png_ptr->filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ sumhi = (sumhi * png_ptr->filter_weights[j]) >>
+ PNG_WEIGHT_SHIFT;
+ }
+ }
+
+ sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
+ PNG_COST_SHIFT;
+ sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
+ PNG_COST_SHIFT;
+
+ if (sumhi > PNG_HIMASK)
+ sum = PNG_MAXSUM;
+ else
+ sum = (sumhi << PNG_HISHIFT) + sumlo;
+ }
+#endif
+
+ if (sum < mins)
+ {
+ best_row = png_ptr->paeth_row;
+ }
+ }
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+ /* Do the actual writing of the filtered row data from the chosen filter. */
+
+ png_write_filtered_row(png_ptr, best_row);
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ /* Save the type of filter we picked this time for future calculations */
+ if (png_ptr->num_prev_filters > 0)
+ {
+ int j;
+ for (j = 1; j < num_p_filters; j++)
+ {
+ png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
+ }
+ png_ptr->prev_filters[j] = best_row[0];
+ }
+#endif
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+}
+
+
+/* Do the actual writing of a previously filtered row. */
+void /* PRIVATE */
+png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
+{
+ png_debug(1, "in png_write_filtered_row");
+
+ png_debug1(2, "filter = %d", filtered_row[0]);
+ /* Set up the zlib input buffer */
+
+ png_ptr->zstream.next_in = filtered_row;
+ png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
+ /* Repeat until we have compressed all the data */
+ do
+ {
+ int ret; /* Return of zlib */
+
+ /* Compress the data */
+ ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
+ /* Check for compression errors */
+ if (ret != Z_OK)
+ {
+ if (png_ptr->zstream.msg != NULL)
+ png_error(png_ptr, png_ptr->zstream.msg);
+ else
+ png_error(png_ptr, "zlib error");
+ }
+
+ /* See if it is time to write another IDAT */
+ if (!(png_ptr->zstream.avail_out))
+ {
+ /* Write the IDAT and reset the zlib output buffer */
+ png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ }
+ /* Repeat until all data has been compressed */
+ } while (png_ptr->zstream.avail_in);
+
+ /* Swap the current and previous rows */
+ if (png_ptr->prev_row != NULL)
+ {
+ png_bytep tptr;
+
+ tptr = png_ptr->prev_row;
+ png_ptr->prev_row = png_ptr->row_buf;
+ png_ptr->row_buf = tptr;
+ }
+
+ /* Finish row - updates counters and flushes zlib if last row */
+ png_write_finish_row(png_ptr);
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+ png_ptr->flush_rows++;
+
+ if (png_ptr->flush_dist > 0 &&
+ png_ptr->flush_rows >= png_ptr->flush_dist)
+ {
+ png_write_flush(png_ptr);
+ }
+#endif
+}
+#endif /* PNG_WRITE_SUPPORTED */
projects / apitrace / commitdiff